Don't buy anything less than a 128GB. Yes, the OS and key games/apps go on the flash.
Crazy? With all due respect, you must be so disconnected from reality, have you seen the sales and discounts the last 30 days? We're at $0.50/GB. We're at nirvana! If you can't afford this, you should just stick with spindles and decay away!
Yes, the prices of SSDs are crazy compared to the prices of HDDs. I can get a 1.5TB HDD for $80, so I do think that $450 for a 300GB SSD (which is $1.50/GB) is a bit high. You're right about getting 128GB, though. From that point down seems to be really inexpensive for some reason. There's plenty of 128GB SSDs for under $90, but jumping up to 160GB adds $100. Weird.