Well, of the two books I thought I might have to buy from Amazon, earlier in this thread, the prices dropped again, and one of them became cheaper than at Google Play (although I haven't checked back there, maybe there was a price war?) and I bought it.
I don't think I'm very likely to make a net gain on my TBR this year. I have been reading a lot of pbooks lately, though, so the value of the books I have read is way more than I have spent. I'll take that as some consolation.