GeoNit's matrices above are well done, and definitely an enhancement to the site. However, I think it's important to point out to users that when you have multiple acceptable zones, if you follow the matrices above and increase your bid each time, you may very well not end up with the absolute lowest possible bid.
For example, let's look at GeoNit's last matrix, for four acceptable bid zones with no free rebids. You're seeking the absolutely lowest possible price. Unknown to us, the lowest price that Priceline will accept for a hotel in zone A is $51, zone B is $60, zone C is $54, and zone D is $58. So we start at $50, and go down the matrix:
Bid 1--Zone A, $50--rejected.
Bid 2--Zone B, $51--rejected.
Bid 3--Zone C, $52--rejected.
Bid 4--Zone D, $53--rejected.
Bid 5--Zones A&B, $54--accepted in zone A.
Result? You just overpaid by $3. But then again, you got multiple rebids by using the strategy--if you didn't, you might not have gotten a win at all, or might have overpaid signicantly more than $3. So it was likely worth it. But I think it's important to know the potential cost of using such a strategy.
A different option would have been to bid $50 on zones A, B, C, and D (individually), $51 on zones A&B and on C&D (which would have been a winning bid in this example), $52 on zones A&C and on B&D, $53 on zones A&D and B&C, $54 on zones A&B&C, $55 on zones A&B&D, $56 on zones A&C&D, $57 on zones B&C&D, and $58 on zones A&B&C&D. If you would have done this in this example, you would have won your bid at $51--the absolute minimum possible amount, and the most that any winning bid would have overbid is $1--but, on the other hand, if $58 had been rejected, you'd be out of bids for the day, while GeoNit's matrix would have had more bids remaining. It all depends on what your objectives and priorities are.
Also, all of GeoNit's multiple acceptable zone matrices and my altered bid strategy above are most effetive if the zones are equally acceptable to you. But we all know that this is rarely the case--usually, our thought process is more along the lines of "My first choice is to pay $xx for a 4* in Zone A, second is $xx for a 3* in zone A, third is $xx for a 3* in zone B, fourth is up to a higher amount of $xx for a 4* in zone A...", etc. etc. etc. And for these situations, using any of the matrices above AS-IS won't work. Instead, you have to doctor a matrix yourself that meets the needs of your bid attempt, but that also meets the rules of PL (regarding things like not bidding for the same zone level/star combination multiple times, etc.). For this, both GeoNit's and my matrices are excellent ways to learn more about how to set such a matrix up. But there can be no cookie-cutter matrix we can put together for you to use, as no matrix can anticipate the infinite possibilities that could come up based on anyone's individual bidding priorities.
Another side note--I had one person write to me to ask why the order sequence for my matrices (in the other permutations thread) for "X" free rebid zones differs from GeoNit's matrices for one acceptable zone / "X" free rebid zones shown above. The answer is--They don't, really. Both my and GeoNit's matrices work through every possible combination, and because they're only differing in the sequence that the free rebids used, whose sequence you use doesn't really matter. (But note that you can't just do them randomly, or you'll have past combinations lock out future rebids. You need to use a planned sequence, such as the ones that GeoNit and I lay out.) I would suggest that mine may be slightly easier to use, as GeoNit's matrices require you to start a new bid every single time, while mine allow you to use the "add a zone" rebid feature in Priceline on every other bid, saving a few minutes. But the end result is exactly the same, and you will have a successful bid at exactly the same point--so use whichever you are more comfortable with.