As a former BB employee, I shall attempt to clear up some of the confusion
1. Best Buy has teams of individuals who run around finding out what the other stores are going to have for sales. Once they find this information, it is distibuted to the stores that are local to the sales. They have an automated signing process, where the signs are printed out at each Best Buy. The merchandising teams are responsible for distributing these signs throughout the store. It is possible that some of these stores did not get their signs and therefore no one knew about the pricematch. I talked to a former co-worker, and he said that they had not recieved any "email" regarding this pricematch. You can tell that it is a pricematch, and not a sale price because it is signed @ 129.97. The 97 cents, as opposed to 99 cents, tells you that it is not a regular price or sales prices. Also, if you ever see a product listed with 50 or 70 cents at the end, then this is a closeout item and the store will not be carrying any more of that item.
2. Regarding rainchecks, the proper procedure is to only issue rainchecks for items that are in the sales flier, and only if there is not a "no rainchecks" disclaimer. It would be ludicrous for a store to offer rainchecks on anything in the store. They are not there as a mail-order business. If someone got a raincheck, then it was either from an incompetent employee, or it was because they talked to/badgered a manager, and manager's don't have a clue; their job is to make the customer happy. Most of them will do just that, rather than what is company policy.
3. As far as why the price is so cheap, keep in mind this is a price war. CompUSA had a special sale, with $150 off instantly from several products Sunday and Monday only; if they're still offering it now, it's probably because Best Buy kicked it up a notch and decided to offer it for the week. If you're worried about the quality of the drive, then keep in mind that it appears to be a plextor drive; plextor makes some of the best cd/dvd/cdrw drives on the market. If that doesn't convince you, then I'd suggest getting the drive @ Best Buy and investing the $30 in a 3 year service plan.. that way if the drive breaks down, you can bring it back to BB for a replacement. And 3 years is a loooooong time.
4. As far as the Best Buy website is concerned, don't be too surprised if you find something in the store that's not on the website. The site is fairly new, so they sometimes are a little slow updating it, and other times a product will come an go before they have a chance to put it up. It's highly possible that the drive is on some sort of clearance, but I think it was more of a "New Years Deal" pricematch-gone-out-of-hand sorta thing. Also, you'll often find product on the website that is not found in any store. This is part of BB's attempt to broaden the product line that they have available and push for more internet shoppers. This will help relieve a lot of the strain on the stores as well as increase revenues.
Hope that helped a little