Re: Providence +100000 to win Big East
You'll get far better odds just betting individual moneylines. Pomeroy has them 23% to beat Marquette. Even if we assume they have a 23% chance to win all 5 games, which is extremely generous as they'll face much stiffer opponents than Marquette in the later rounds, that works out to 1554/1.
Because of the structure of the Big East tourney, we can get a better estimate of the various situations surrounding a Providence run to the championship. Using the Pomeroy may give a rough estimate, but doesn't reflect actual bettable numbers.
In the first 3 games, they will meet Marquette (+270 ML), West Virginia and Louisville. Discounting the fatigue factor corrections, they will be around a +330 ML dog to WV and a +380 ML dog to Louisville. This means you can get around a 75/1 ML parlay to get to the semis.
In the Big East, all teams except Seton Hall/Rutgers, South Florida and Depaul have better power ratings than Marquette. So unless there is a series of big upsets in the tourney, the semi and finals will be at least +270 ML on Prov, giving a ML parlay of at least 1040/1. If they face ND in the semis and Pitt/Syracuse in the final, the ML parlay will give at least 1900/1 odds.
The only huge advantage would be if South Florida and Depaul win 3 and 4 games respectively and meet Providence (around 200/1 ML parlay best case). Like most future bets on severe dogs, the value depends strictly on meeting other big dogs in future rounds. In this case, the probability of the other huge dogs winning 3 or 4 games is extremely small.