DVD-R came out first. So Spinner is right. But not knowing enough about details of situation I tend to go more with more universal compatibility for the things that hurt more to replace. Right now, cost for a multimodal drive has dropped enough (If we are not talking DVD-RAM) that it is probably the better overall buy even given cost because the newer drives tend to be faster as well as multimodal.

Whichever of plus or minus stabilizes to be more popular will have cheaper media. For another example that relates as to popularity vs cost, take current BetaMax media costs versus VHS. Rarer costs more in part because rarer.

If possible and within budget to get something that straddles both standards where the standard is being settled into place, straddle if can.