[Perdition]

Currently you can set up an automatic shopkeeper, place your items and... buy your own items from that shopkeeper. With the tax system this comes out a net loss each time, but I can't imagine it being intended behavior anyway and it probably leads to other abusable bugs. All that aside, it just makes 0 sense.

[Neus]

This is intended, yes. I'm not sure what could be abusable about losing your money buying from yourself, though.