I've bought pre-modded cars in the past - you can get real bargains - the rule used to be, and still is in many cases that what you spend on a car to mod it you take off at resale time!

Unless you can find someone like minded it can be hard to sell a modded car - the ones I bought I got cheap and turned out to be great cars as they had been loved by their owners. Same with factory options, you'll only get back a fraction of what you spend on most options.