I just moved onto a 1970 Uniflite 36' Houseboat and I just love waking up on the water - my expenses went a little higher than I had expected, but hey I am in Southern California and it is still sunny and warm here. Ask grandma to send cash for my birthday
Slip = $600 (w/parking, electricity, showers, water hook up, mailbox included)
Boat Payment = $500
Boat Insurance = $35 (got a great deal at BoatUS, under $400 for the year)
Pump Out = $45
Repairs = $200
Extra stuff = $50
Total = $1,430 or so (extra things are still cropping up as I go along)
But, I do not have a phone line on the boat (just use my cell) and no cable or internet. I cut out most of the extras in my life for now and just pay for food, car, etc...
Hope this helps. You should really go for it, I love going home every night to my little floating palace. I work on it every weekend, it is my "first home".