Well, after about a week, I finally took apart the Makita 18V packs to see what shape the batteries were in. I examined each group of cells to see which ones are good and which ones aren't.
Of the 5 packs I bought, 2 have all 10 cells working. 2 had 8 cells out of 10 working and one that ha only 2 good cells out of 10. I guess that's 38 good cells out of 50 which averages out to be around $1.71 per good cell which is a tremendous bargain. That's $17/pack and about 80% cheaper than a new pack.
Of course, finding these packs is not extremely easy. You have to find a reputable reseller of recovered rechargeable batteries and be willing to accept a fair inconsistent set of batteries, find the bad ones and replace them and then reconfigure the packs to your liking. It's a fair bit of work, but the price is right.
Here's a shot of a Bosch Fat Pack opened up alongside 2 Makita packs. Similar sizes but the Makita packs are stacked evenly and not staggered like the Bosch.