I have an Ibanez V70CE Acoustic-Electric guitar. While it was not expensive, I like the way it feels and it sounds just fine. The problem is it doesn't like to stay in tune. I always use high quality strings and I replace them regularly. So my question is would it be worth it to pay someone to upgrade the tuners or should I just put my money into a higher quality guitar?
Most solid, durable tuning machines are very cheap relative to the price of a brand new guitar. Also, remember that tuning issues are not simply localized to the tuning pegs and machines. Check out the answers to this topically related question for some ideas on other factors to think about when your guitar isn't staying in tune. Were I you, I would ask myself "Do I really want another guitar, or can I live with the one I have?" knowing full well that a new guitar might not fix your tuning problem. The new instrument you get could suffer from the same or different problems that the current one does. I'd get to the root of the problem and find out exactly why it keeps going out of tune, and then make my decision based on that--and of course how much I wanted a new guitar ;D.
One last note: guitar companies that mass produce lower end guitars tend to find places to skimp such that the instrument is affordable. One place I have really noticed this is in the tuning machines. You can get a set of tuning machines from StewMac or your local guitar shop for a good price--just make sure they are hot-swappable else you'll be drilling new holes.
Are you sure the tuners are the problem? Even with fresh strings, they may well stick at the nut, slip at the tuners (if the strings aren't properly anchored), or slip at the bridge (if, for example, the ball end is initially pushed too far into the guitar).
Do the tuners seem overly loose?