I have a mid-2010 iMac and for some reason, DVDs are not working in it anymore.

First let me say this...I rarely use the DVD drive on my Mac. It is no way "overused". I think the last time I used it was a few months ago, possibly prior to Mavericks upgrade and it worked just fine. Last night, I put a DVD in and I could hear it spin and try to read the disc. After 3 cycles of trying to read the disc, it ejected on it's own. Thinking that maybe it was a bad disc, I got another DVD that I know works and put it in. Same results. I turned to the forums here and tried what everyone suggested. I reset the PRAM and the SMC(?). No luck, same results. I used canned air to remove any dust from the drive (I don't have a lens cleaning disc, but I will pick one up to try). No luck, same results. I don't see how the drive could go bad when it mainly sits unused. Apple care has expired, so I have no idea how much this is going to cost me if the drive needs to be replaced. Are there any other remedies out there? Something I haven't tried?