I think a maid would cost you that for 1 year or max 2 years (since we are talking 24/7 around the clock care). So assuming that the robot would be capable of functioning for anything more than 2 years would already bring you in a solid gain even if it were to cost up to 100 000$. Now assume it would be able to function for 5+ years (with maybe some minor 20% maintenance costs), the price point for purchase could easily be increased by the seller to a few hundre thousands easily.