Although I am very leery of doing this, having been burned before, I just recently bought a couple of these modules through ebay from a vendor in Hong Kong. I half-expected to have thrown my money away, but the unit I have installed fired right up and works just fine. It had apparently never been installed; all the gold-plated pins were still unsoldered. We did have one pin fall off due to excessive solder heat, but we were able to pry off the lid, re-solder the pin to its pad on the internal substrate, and after that, it worked just fine.
I suppose that someone might be harvesting used devices, prying the lids off as we did, and soldering on new leads...but if so, they are doing a good job, and if it works and keeps on working, I'm not gonna worry too much about its pedigree.
YMMV, of course. Just do a ebay search for MHW812. I paid about $26 each for two.
The other popular STL module, the MHW808A4, is still rather more readily available from traditional stateside suppliers, like RF Parts and RFMW.
Equipment repairs are my business; let me know if I can help fix anything or sell you any parts.
