Yep Dast, tightwad I must be!
I agree, I don't enforce a rule either, there are reasons to buy the latest if you have a strong social reason to do so, but at the moment the thought of playing online against loads of people I don't know and getting my arse kicked as they practice 10x more than I can doesn't seem that interesting. I prefer playing games against people in the same room and relatively the same skill level (eg the same amount of free time) - probably comes from the Amiga days!
I will be grabbing a PS3 at some point this year, as my friends are pushing me to get one. I'm not paying over £200 though!