The more expensive tires are the least expensive.

[BikePacker]

The cost of the tires (& tubes, if i'm running 'em)
when compared to the total cost of a tour,
both in dollars and time spent organizing and executing,
along with the justifiably based added peace of mind while on the spin,
makes the decision for me.

[canalligators]

On bikes that go on tour or are ridden a lot locally, I don’t skimp on tires or braking.  They last longer and work better.  Same holds true on my motor vehicle.

[John Nettles]

One reason I believe it is a good idea to buy the best quality tire you can afford is that the tires are what keeps you upright on the road. 

Think about it, you basically have around 1" of tread keeping you upright on a 225+ pound fully loaded bike going down a twisty mountain at 45mph.  If the tire doesn't grip well, isn't strong enough to prevent blowouts (or roll offs!!), or prevent sidewall punctures on gravel roads and you risk a true blowout, then you could be toast. This is especially true of front tires because a blow out at even 10mph on the front can easily cause you to slide out before you know what happened.

Same philosophy is used for my car tire.

[Pat Lamb]

I get twice as many miles and one tenth the number of flats out of tires that cost twice as much. And I don't want to waste time in Gaastra, Michigan looking around to see if I can find suitable replacement tires, which you won't be able to.

While I agree with the sentiment you and Westinghouse advocate, I wonder where the guidance breaks down.  $20 tire twice as good as a $10 tire?  No argument.  $40 tire twice as good as a $20 tire?  Maybe.  But is a $100 tire twice as good as a $40 tire?  Hmmm...

And for some of us, flat resistance and longevity aren't the only criteria for comparing two tires.  Some tires achieve flat resistance through thick rubber and extra belts.  Those work; but IME they compromise the comfort of the tire (like rolling on wood with a little give), and if such a tire does have a flat, good luck getting that sucker off the rim!

So do you accept those trades, or is there a sweet spot somewhere in the middle price range or the middle weight range?

[HikeBikeCook]

To me safety is the first concern, as John pointed out. Can the tire support a loaded touring bike and does it have a good reputation for safety. Next comes flat protection - flats are not the same as blowouts - both result in a flat tire, but a blowout is more likely to take you down. Next is handling and ride, I guess that is comfort. Some tires can check all the boxes pretty equally, but if you put your three of four must-haves into a 1-10 rating scale, I am looking for a tire that ranks at least a 7 in all areas.

[staehpj1]

I get twice as many miles and one tenth the number of flats out of tires that cost twice as much. And I don't want to waste time in Gaastra, Michigan looking around to see if I can find suitable replacement tires, which you won't be able to.

While I agree with the sentiment you and Westinghouse advocate, I wonder where the guidance breaks down.  $20 tire twice as good as a $10 tire?  No argument.  $40 tire twice as good as a $20 tire?  Maybe.  But is a $100 tire twice as good as a $40 tire?  Hmmm...

And for some of us, flat resistance and longevity aren't the only criteria for comparing two tires.  Some tires achieve flat resistance through thick rubber and extra belts.  Those work; but IME they compromise the comfort of the tire (like rolling on wood with a little give), and if such a tire does have a flat, good luck getting that sucker off the rim!

So do you accept those trades, or is there a sweet spot somewhere in the middle price range or the middle weight range?

As with most things, I suspect there is a law of diminishing returns.  Where the sweet spot lies may depends on you needs, tastes, and the thickness of your wallet.

Also as you point out we all have different criteria.  There is puncture resistance, resistance to catastrophic failure, rolling resistance, ride feel, weight, ease of carrying a spare, whether it is tubeless ready, and a few others.  We don't all value them the same.

Then there is the fact that pricing isn't always rational.  Sometimes something actually can be a bargain.  Also sometimes an over rated product can be grossly over priced.

Still, it is worth spending enough to get a good tire.

[DaveB]

Like a lot of products, bike tires have a "sweet spot" for cost as it applies to the majority of riders.   Much less and the durability, ride quality and uniformity suffer.  Much more and you are into specialty race oriented tires where durability is sacrificed for low weight and low rolling resistance.   

[froze]

8 punctures seem like a lot for a Schwalbe Marathon (though you didn't say which Marathons you used), but that is a lot of miles too, so not sure what to think; I have heard from some tourers that they never got a flat using the old Marathon Greenguard tire, which I think is the new Marathon Plus HS440 improved a bit.  On my old touring bike I used the Greenguard and never had a flat with those so I think the Plus HS440 will be at least equal to that.

On my camping/touring bike I decided to go with Schwalbe Marathon Almotion Evolution tire, because they have long tread life, they have the highest degree of puncture resistance, and they had the lowest rolling resistance of any touring tire with low weight at 490 grams.  After reading that the poster had 8 flats, while not bad but can those flats be reduced further?  I'm not sure, but I decided to put a set of Mr Tuffy Ultralight liners in my tires and see what happens.  The Almotion Evolution is a TL tire, but it can be used with a tube no problem.  I just bought these tires, I tried to get them 8 months earlier but there were none around till last month and then I found 2 only and they were on sale?!

The Marathon Plus HS440 is their best flat resistant tire, in fact they call it flatless, which I highly doubt, but I'm sure it has the highest degree of flat protection bar none, with the highest degree of durability that was similar to few other models.  I didn't choose this tire because the rolling resistance was quite high as was the weight at 960 grams.  So while I liked the idea of the tire, I also didn't want more work to keep the bike moving, and at the end of a day of riding my legs would be more tired using the Marathon Plus vs with the Almotion, so that was my thinking process for getting the Almotions.   I do know from using the Greenguards you could feel the weight and the sluggishness of the tire as the day went on.

While the Mr Tuffy Ultralite liners do weigh 52 grams but still even combining the weight of the liner with the tire it's still significantly lighter than the Marathon Plus tire by over 400 grams!  I also plan on only using the liner in the rear tire since 98% of flats occur in the rear.  I haven't fully decided not to use a liner in the front, but I think that's the direction I'm heading. 

But I would recommend someone wanting to buy a Schwalbe tire is to go to their site and look at how Schwalbe rated each tire then select one that best fits your needs.