They are fairly uncommon and these prices are what they usually go for.
If you're not willing to spend that much, your best bet is to either go for:
-
Vertx Overwhites, also camouflaged. Not in MARPAT but similar.
-
CF -style overwhites (pure white)
- CF overwhites + fabric spraypaint + stencils
Or since the season is over and you have 8 months until next winter, be patient and scout eBay for that awesome deal. They pop up from time to time, I got my snow MARPAT pants that way.