my "enough point", (not in a good way, but OK, ENOUGH!) was purchasing a lovely samsung note II with a stylus inside through verizon and paying through the nose for it and its service plan, and then discovering a couple of years later that my loving care of the device was pointless, the OS was outdated and app after app stopped being supported. I threw in the towel and got a cheap samsung with tracfone. i think $60 for the phone and about $10 a month for minutes, I just refill when I get low.
the experience is definitely not as nice, and 30 months in I'm starting to feel like the phone's not working as well as it once did, but I think I'd still rather go this route even though I do use the phone for a lot of things. maybe i'm being too cheap ...