This is actually a cool idea. Have an experienced dm in the house, have a website where people sign up (1 person upto a full party, or you can join other people's parties if they mark it as public. ). Have a one off campaign with the group, have some food and maybe a few light drinks, 3-4 beds for people. Charge $150-$200 per person per night... I could see it working. Say 4 times a months, parties of 5, that's $3000 a month. Could probably pay mortgage and the food and drinks. Make it every Friday, Saturday and Sunday... That $9000 a month, easily cover expenses in a major city and probably afford the dm a comfortable life...