I have 2 wheelsets. It would be easier to have two bikes, obviously, but much more expensive. I think the trick is to get wheels that have the same dish and are the same width so you don't have to adjust the brakes each time you switch. For me, I have the same wheelset. One with size 25 road tires and the other size 32 cross tires. Throw the bike on the stand and 2 minutes later, I'm ready to go.
Price depends on what you get. You can get a decent set of wheels for around $200-250.
__________________
Demented internet tail wagging imbicile.