You should not be able to buy it. If someone is selling it, the author (me) is not benefiting.
There is a longer story, but the short version is that Homecoming is one of the products I wrote for QLI which was not paid for. I released it under the Avenger license but was forced to remove it from sale. QLI had, I was told, an exclusive license for the Gateway region though this was never confirmed by Marc Miller. In short, QLI never had the right to publish Homecoming as they did not complete their end of the deal (to pay for it) and the text remains my copyright. I hope to do something with it one day.