That's a big house for only 3 people. I don't think this is the first time I've heard about people from that show struggling afterwards with bills and such. I don't understand why they don't do a more practical sized house. *shrug*
I stopped watching that show a few years ago. I realized ever episode was alike and got bored with it. I really just wanted to see more of the house and less of the hosts crying.
man, you nailed it - i feel exactly the same way. i feel like a peeping Tom, watching such personal family stuff going on and all the crying... no thanks.
as for why the homes look like they do? check out all the advertisers

they employ pretty much every advertiser in each of those homes, from the appliances to the furniture. its all product placement - and they do a fantastic job of outfitting those homes.
but i do agree that it must be a shock to go from one to the other in a week.. and then pay those bills. i dont have any problem with the family selling the house if it becomes a financial/emotional burden. we have 4000 s.f. and it is a BIG job .. and a lot more upkeep.