I would just be sure that you actually own the domain, not the service. Early in my life was a web developer, I made this mistake, and it took a bit of effort to wrest ownership of the name back.
I use Dotster, and have found their service and interface perfectly acceptable. They, too, sent me an email saying I should I should renew my domain name before the rates went up.
The cost of the it is probably a few orders of magnitude less than the time you need to spend to come up with a good domain name. Thus, it's really not worth it to consider domain price as a decision factor.
Now, as far as functionality goes, namecheap.com is pretty good.