1. I am having a hard time finding information on the cost of camping along the way. If anyone who has done this portion of the route can advise me on this it would be very helpful. I am on a limited budget and would like to have an idea for planning purposes.
Assuming that you'll be camping mostly in National Forests, plan on spending up to $20 a night in developed campgrounds. And "developed" campgrounds in National Forests usually mean pit toilets and a water pump. I've found that campground fees vary widely, even in the same National Forest. This because many National Forest campgrounds are run by contracted private concessionaires, and they are the ones who set the price. (In fact, there can be multiple concessionaires running campgrounds in the same
National Forest.) Less developed campgrounds may be cheaper, a few may even be free. But these ones may not have a (treated) water source.
Of course, one of the advantages of riding through National Forests (and BLM land) is that you can pretty much camp anywhere for free. Check in with the local ranger station to see if there are any restrictions.
National Park campgrounds have a little more in the way of amenities. (Flush toilets! Sinks!) Looks like camping in North Cascades National Park run $10-12, don't know what it will be in other parks. (For comparison, regular campsites in Glacier (not on the Sierra Cascades) were $20, however, they had hiker-biker sites for $5 a person.) You can't free camp in a National Park, though.
Private sites are a crapshoot for prices, though $20 a night is a good average to prepare for.
Hope this helps.