I dont think the S2 will come down in price anytime soon, not until they anounce a newer model which wont be until the spring cycle. So if you can wait that long. But like computers, there will always be something better or cheaper downt the road. One rule that is true with pretty much all electronics.
Figure our what is the most you can absolutely spend, and get the best camera you can get with that amount of money.
Dont skimp on 100 now and curse yourself if you want to take a video down the road. Sure you dont neeeeeeeed it, but then who needs half the crap we buy. Skimp on some dinner dates. pass up two of those and there is your 150.