That depends on what country you are in. Here in NZ Android phones actually seem to hold their value pretty well, about as well as iPhones.
One year after the Evo 4G came out, no one would even consider $90 for it. I had the original box, all original accessories and a case. I ended up selling it back to Sprint for $80.. And that is here in Los Angeles where Craigslist is always hot! Lol..
Honestly I had my Evo fully rooted and running a personally customized ROM, but it never worked the way I wanted it to. It was a cool phone don't get me wrong, but it has nothing on the smoothness I get from my iPhone.
People always tell me, well Macs and iPhones are for people that don't know how to customize or make changes manually, they aren't for skilled people.
I think this is just wrong. Before I switched to Apple, I had built many custom gaming PC's and had numerous Android phones. My life was all about the PC and Android.
But let me say this.. Even if I know how to customize and make everything "just work" the way I want it to. Why am I paying a company $$$ to give me a product that I have to customize just to get it to work right.
When I pay big $$$, I expect programers, engineers, and developers to do all the thinking for me. If I want to tinker into my enthusiast side, then I might consider a custom built PC or Android, but that is strictly for a hobby.
Simply put, nothing I have used has been up to par with what Apple comes up with in Cupertino. Will it always be like that, maybe, but probably not. If another company comes up with something that is leaps ahead of what Apple is producing, I will gladly make the switch. Eg - Windos phone 7 is pretty cool actually.
Remember you can usually test a product for 30 days and exchange it if you want to.