Tire alignment

Do you have any unusual tire wear presenting on the old tires?

4 hours is excessive, IMO.

Check ride height (3 valves).

Check caster (changed with wedge shims, so unlikely to be out. Yes, of coach pulls to one side and swapping front tires does not cure it, then caster may be out).

Camber not adjustable (unless bend axle).

Toe-in easy to set/adjust. Can use either long stick or machine to do it.

Yes, if "dog tracking" or other issues, then an alignment will cost more.

Do any of your tires show any unusual wear? If not, forget the alignment.
If they do show unusual wear, go for the four wheel thrust angle alignment, which for $500, is what I think they are providing.
If the shop can't do a four wheel alignment go to a place that can rather than having just the front end aligned at a high price.