Well, if you want to save both time and cash, Prodisc +R non-printables (plain silver) is the answer.
Ritek's Richojpn is good, long lasting and very inexpensive. However, sometimes, quality control scans go out of spec beyond the 4320 mark. This is at the very end of the disc. Should you encounter this problem with the otherwise great media, just set your recording software to a custom size disc of 4320. Personally, I do this with DVDshrink, but it can be done with almost any recording software.
Legacy +R is extremely cheap and provides either Prodisc or BenQ (AZ2), and you may need the latest BenQ firmware if you happen to get AZ2, but otherwise, this is good media and burns to 12x speeds.
Media to avoid would include nearly all printables or other discs with a hard paint on top. Clear or frosty laquer is okay, but opaque paints are thicker and harder. Given imperfect storage and about a year of time, the hard paint will have flexed at a different rate than the disc. This creates a "coaster" but almost all of the information can be retrieved through data extraction. This problem can be prevented by storing printables in DVD cases. However, avoiding printables can save you both cash and headaches. Labels can be removed from silver discs, and when a label is removed, any label-inspired problems leave.
BenQ drives can overspeed many 4x medias to 8x. This technology has improved with the T9 firmware to provide better data integrity and better playback, even oversped to 12x. It is usually not worthwhile to overspeed to 16x in order to gain 20 seconds faster speed.
If you have T9, you could also use the CMC medias. Philips branded CMC seems to be high-grade, and the F01 (Philips +R 4x) burns at 8x for a price of $16 per 50 discs from Tiger direct.
When purchasing cheaper discs, you will sometimes have the option of the same price per disc regardless of the size of the packaging. In this case, opt for the smaller packages because they are much more resistent to shipping damage and thus give much higher quality results.
There IS a lot to consider for media besides price.
Does it perform in the BenQ?
Does it consistently maintain data integrity?
Does it play back skip-free in all of MY set-top players?
Does it last?
As you can see, those four factors are much more important than price. Some medias can annoy you by giving inconsistent results in one of these four important factors. Inconsistent medias will often have a low price, but they are most expensive of all.
So, go shopping for good deals on media (check CDfreaks Deals forum), research the media (check CDfreaks media forum), look at videohelp.com to see if your set-top player will like the media (check lists section) and make the BenQ forum the last stop to check ("post-your-scans" and other threads) and see if the good deal agrees with the BenQ drive.