What troll said.
Let's see, sub $200,000 house, $100 per entry, if they don't get at least 2000 entries they promise to return the money, hmmm....
But if they get 10,000 entires, why! that's over $800,000 profit! Incidentally, assuming equal chance among all participants and 2000 participants, you would be spending $100 for a 1/2000 chance to get less than $200,000 which works out to an average of less than $100. So on average you would almost be breaking even -- which isn't bad for a lottery. However that's the optimal scenario. Far more likely is one of the following:
-- there will not be 2000 applicants, so you hope you get your money returned.
-- there will be more than 2000 applicants, so your average return will be less than your investment.
-- there will be collusion with one of the supposed applicants, and you will have wasted $100.
In other words, this doesn't need to be a scam based on a reference to "void where prohibited", since even if the contest operates as advertised, the sellers only stand to make money.
Incidentally, I'll give a 1% chance of winning $1000 to anyone who sends me $11 by paypal and a picture of a smiley face. Void where prohibited.