You're never going to get a dollar for dollar return so unless you actually need/want the feature, it's pointless to pay extra for it.Not to mention resale value can only be helped, if anything.
That said, I regret cheaping out and getting my dad the wifi-only model (paid ~$250 after tax and Best Buy iPad 3 trade-in). My justification was he was only gonna use it at home. My parents just scheduled an overseas trip for next year. Ugh.