I've got a mid-nineties Standard (bought new) which is a cracking guitar - made when Gibson quality (on average) was very high. They're pretty reasonable money used, probably around £800-£900 depending on condition, and I'd buy one over a Japanese LP for that amount of cash.
A copy (to me) is always worth less than the original. The Japanese LPs are great if you can get them for under £500, otherwise I'd go for the Gibson every time.