I use -R inkjet-printable discs, too (all hub-printable). That said, the option I've found that best ballances quality with price seems to be Prodisc. The ones I've had (two diff batches from two diff vendors) were MCC02RG20, and burned at 8x (as advertised). Kprobe scans showed them to be very good media (PI under 30, PIF under 3 with my NEC 3500, and PI under 9 and PIF under 2 with my Pioneer A09).
I've also had pretty good luck with the Optodisc 8x (OPTODISCR004) and High Speed 8x (also MCC02RG20). The Dupsonics are horrible. Its mediacode shows TY, but it must be faked as none of my 5 DVD burners can produce anything remotely decent (assuming Nero doesn't just quit during the process). Which is ashame, becuase it was the only printable surface I've tried that didn't seem "sticky." BeAll (BeAll G40001) was also bad, although the burns did at least finish.
Prodisc so far is the best quality/price (for me, at least). The surface holds ink well, although like any other printable media I've tried it always seems "sticky" and the ink will smear if you get near water. I guess thats just the nature of the beast?
I can't vouch for any on-line vendor (because I don't know where you're from), but I do really like Rima.com, although thats the only one I haven't orded from. The reason I like them though is from the email conversations I've had. They seem VERY customer-oriented and willing to bend over backwards to help (more than willing to send out free samples for you to try). The only down-side is they don't carry the cheapies that I like.
I've had trouble with many of the others, though (Supermediastore.com flat out lied about free shipping, Meritline.com sold misrepresented discs as hub printable, then wanted me to pay to send them back, and currently Allmediaoutlet.com is ignoring emails about the above-mentioned Dupsonics). Whoever you do go with, though, check out these forums and places like resellerratings.com (presuming you'll be ordering on-line and not going to B&M)