I am new to this site, and would like as much help as possible. I am close to buying a 2002 JCW. I just did a pre purchase inspection. I was told that the engine is leaking, but they don't know what. It could be the valve cover, oil pan or the engine. Is this going to be a big problem in the future. And, what is the best and worst case as far as me spending money to fix it. It has 64,000 miles, is clean and they are asking $10,500. Somebody help me, please.

 

Sounds like you need an inspection by somebody who knows what they are doing....
Also there was no "JCW" mini for gen1...but a collection of different items that could be added by the dealer, or ordered, and added later. Check to see which jcw items the car has....
There is a big brake kit, an super-charger/head upgrade, a suspension upgrade, and various other bits....I know I may have missed some, but very few cars were sold with all the kits...some items came out later...the upgrade from the standard JCW to the JCW 210 with the airbox, bigger injectors, and updated computer program, and there were other things like jcw dash covers, steering wheels....
Many cars are sold as jcw, with a few items bolted on...so watchout...do your due dillagance.
The oil leak could be minor...a valve cover, common, or more major, like an oil pan gasket, also common, or any one of many other items...if you are serious about getting this car, find a mini centric shop to do the inspection, or even the dealer...regular shops don't have much luck with mini's...