I would have to say that if you don't have *any* of them and they're all for your collection it might not be such an awful deal ($3 a pony isn't bad), but if you only need a few, then I wouldn't pay that much.
yeah, it does sound like a lot. people who post them on craigslist just know they go for a lot, but not what they are worth. $25 is more reasonable. i bought about 50 g3s with a few fakies for $25. it is up to you, if you have the money to buy them and you want them bad enough, go for it. from what i can tell in the picture, it makes them look like they are in pretty good condition. they look clean and hair cut free.
I agree with Peppermint Truly. If you haven't got any of the ponies (or at least, let's say, 90%), it may be a good deal for you. Otherwise, it's simply too much money for fairly common ponies.