Question 1: First of all, what bargains are available depends on where you are. Europe vs. U.S.A, somewhere in Asia etc.
I’m surprised you’ve had such good luck with Ritek G05s, most reports here peg them close to a house of cards in terms of long term stability
Generally speaking, posters here will only recommend Verbatim and Taiyo Yuden and I’m one of them. Since you’ve already ruled out Verbatim, pricewise, your best bet would be Taiyo Yuden Valueline 8x DVD-R, TYG02.
If you’re in the U.K. you could try these
a 100 pack for 15 squid.
The comments did suggest that they’re not perfect but since you don’t want to pay much more than you paid for Ritek G05s you will have to accept some compromises, that said I used a 10 pack of those once, and they were fairly good. Taiyo Yuden are in most forms, among the best disc for any long term use.
Edit: Just saw they must be 16x, so that would leave you looking for TYG03. At Â£22 (Â£7 more than the TYG02 above) you might try these:
Big thread on that, first sticky in this forum!