Wow...thats a pretty open ended question ! Assuming your truck isn't a basket case that needs a ton of bodywork,a budget of 25 - 35k will get you a pretty nice truck ( either stock or modified ). It would be difficult to recover that amount of $$ on a stock truck. On a modified truck ( rodded ), I've seen a lot of nice trucks selling in the $ 25,000 - $ 35,000 range. Prices have definitely come down over the last year. If you opt to modify it, you can go from mild to wild. Keep the stock look with new running gear, or go full on custom with mega engine, chopped roof, exotic interior, etc. etc. Everyone has their own idea of whats right / looks good. Unless you are " into the build", and have the time to work on the truck, I usually tell people to buy a finished vehicle - your costs are set and you can enjoy it now. My final comment is if you have a lot of freeway driving, the stock setup will not be great. A more moderm engine, trans, and rear-end will be much more comfortable.
Just my 2 cents worth.....