I have only a few restored books in my collection, but everyone I buy is for my personal collection. Sure I keep resale in mind so as not to overpay (so I can at least get cost back on a book if need be), but if I can get a book around 50% of GPA i'm happy. This is only for key issues. I would not buy a restored common or cheap book. If I can get a nice looking copy for around $500 unrestored, i'd rather have that. I do however stay away from trimmed books. Trimming is not for me personally. All that said, i've only been collecting (buying bigger books) for about 4 years now, so this is perhaps a noobs perspective. I, for example, bought an X-Men 4 7.5 slight resto (white pages) last night for $700. It's a lot of money, but for the grade i'm happy. I don't think I would take much of a loss or any if I decided to sell it in the future. Who knows the future. Either way, I feel if it makes you happy, go for it. For investment, restoration is probably not the best approach.