What do you expect?

When I've sold something - am I expected to continue to maintain it out of the goodness of my own heart? It's not owned by me anymore. If the purchaser wants to maintain it and/or pay me to then that's up to them. It's Microsoft which abandoned it, not the individual.

Probably I can't even create a more-optimal product. Any contract worth the paper it is written on would have a clause which says 'you can't go out and recreate an identical product immediately'.

And yes, it's a luxury purchase, but it was an unexpected windfall. They had a job with Microsoft so were presumably making a decent wage that covered their regular expenses already. Why not buy something to make you happy?