Fixer-upper too risky?

So here's the dilemna. Is it foolish to invest $100,000 in renovations (new kitchen, new bathroom, etc.) in a non-doorman, nothing terribly fancy, building on West End Avenue in Manhattan Valley? The bottom line for the 800 square foot apartment will be in the $630,000 to $650,000 range? The result will be exactly what we've always dreamed (I hope). Is it wiser to instead buy an already done apartment which gives us an extra home office/really small bedroom, but also saddles us with a very small kitchen and bathroom in a snazzier doorman building (95th and West End) for the same price? Any thoughts on which choice is the safer or smarter in terms of recouping our investment in five or ten years?