Cheap discs are crap. By name brand good quality discs. Actually, do the same for CD-R as well. Yes, cheap CD-R are still a problem actually. Cheap CD-R aren't as crappy as cheap DVD-R, but I've had problems with recent el cheapo CD-R as well. In fact, I (and my friends) have had problems with even name brand 2nd tier CD-R media.
I pay literally 2-3X as much for CD-R media when it's for backup of important data. I use the cheap CD-R stuff for less critical stuff - temp file storage, secondary backup, sneakernet, etc. I don't buy cheap DVD-R at all because it's so useless. The cheapest stuff is like cheap CD-R of 5 years ago. Won't even burn reliably, and if it does, it may only be readable for a few weeks.