Sure, I'm going to get both, years from now when more games are out and I can get a cheaper used copy. I didn't buy my PS3 for years and then got a used one for $150 and it has been running great with no problems.
A wise policy. One that I honestly should follow, since I don't really do multi-player gaming anymore....the down side is that if I did follow such a policy, and did decide to get back into MP gaming, a lot of the games that had come out initially for the newer systems probably have lost their online support by that time.
One of my favorite Xbox 360 games was Chromehounds. I got in quite a few rounds with a clan I had joined, and then, a couple months later...bam....no more online support. The game was then useless. It had a shallow single player mode, that really was just a tutorial for the online matches.