I know what you're saying, but really, my HDD is not a bottle neck, for me.
Save a file? Unless the file is large (>50MB) you arent really going to see a difference. My HDD's avg read speed is aroudn 40MB/s, peaks out at 80MB/s, so 1-2 seconds to write 50MB. Chopping this down isnt really a priority, for me
p.s. I dont upgrade CPU's all that often, Infact my C2D is about 3 or 4 year old, it's just oc'd to 2.8GHz. In reality though it is a fine performer for what I use it for.
Dont get me wrong, SSD is a good upgrade for most people. Hell, if I wanted to throw £100 at my PC it's probably what I'd buy next.
However if you have the choice, between an SSD upgrade and a RAM upgrade, I'd be choosing RAM. 8GB+ is a massive difference over 4, if you use your PC like I do (6 month sessions with a gazillion browser tabs open(too lazy to clos), photoshop, XP VM's, word/excel, 4 diff browser, irc client etc. They all stay open, and having enough ram is important, to me