IMHO cabinets and countertops are not reusable. Donate them to Habitat for Humanity. Getting the right mix of cabinets is always tricky. Even more so if you have a very limited choice to work from. The only way I'd even try is if they're coming from a large kitchen and I'm doing a small one. Countertops are even more problematic.
With a little creativity I think a kitchen can be re-used. I purchased an entire kitchen on Craigslist for $300 and used it in a small basement unit. The refrigerator was a little too big so I did buy a new one. I painted the cabinets and trimmed the countertops to fit my space. The original kitchen was much larger so I was able to use only the pieces I wanted. I hung the extra cabinets in the garage, saved me a ton of money! Not a great picture but give you an idea.