They're fairly affordable. You can get ones big enough to put windows and your swap file on for $100. Intel has a 40GB model, and a whole slew of companies have 32GB models at that price point. The performance isn't as good as the larger versions, but they still pwn a normal hard drive.
http://www.newegg.com/Product/ProductLi ... &name=32GBOf course, with VAT, it'd probably be a bit more than $100.
Stupid protectionism and tariffs.
As an aside, I still love the SSD in my main machine.