My preference is to take my bike on the plane with me (on Frontier or Southwest), assemble it in the airport and ride out the door. On the way home, it depends on whether I have a friend with a car who can drive me to a bike shop to get a box, and then the airport. If I do, I'll bring it home the same way. Otherwise I'll ride to a bike shop, have them do the pack and ship, and take public transportation to the airport.That is my preferred way to get the bike to the start of the tour.
On the way home I have generally found it easier to just drop it at a bike shop and let them pack and ship it like you do as your second option. That has always cost me around $100 including packing and shipping. I figure it is worth it at the end of the tour to be able to just drop it off and forget it rather than deal with boxing a bike in a strange city and then getting it to the airport.
The bike shops seem to get a better price on the shipping than I would if dealing directly with the shipper, so some of their packing charge is offset by that.\
BTW, I avoid going to a UPS store and having them ship. Both times I did that the price was crazy high despite it being the same size and weight as when I paid way less via a bike shop.
I think that since I moved to Florida it may be a little more expensive, because when we shipped our bikes home from Reno my bike was ~$100 to Baltimore and my daughter's was ~$125 to Tallahassee. That was with same size boxes and about the same weight (actually her's was slightly lighter).