I'm a believer in the suicide pools. There are 2 of them in I play that each charge $200 plus a $30 rake/admin cost. The last five years they've each had 1000 + entries. Some years 1 winner, other years 20 winners have lasted the whole season.
The attraction for me is the number of social gamblers who join the pools. The first week you see some people taking teams like Dallas at the Giants or Miami at Houston. I'm guessing they're casual fans who are betting on their favorite team. So even though I'm paying juice to the pool operators, I figure it's more than compensated by the people who put money in the pot and don't stand a chance. So my 230 entry fee has an expected value of about 300 or so.
I'm sure there are pools around where everybody is sharp, but they probably charge something like 1k or 10k for an entry. I prefer to buy 4 or 5 entries in the softer pools.