As the others said, contracts of less than 150 points (especially <100 points) often sell at premiums. And, if you have a lot of points, it is better to have multiple smaller contracts than one big contract because contracts cannot be broken up and big contracts are harder to sell.
However...in considering buying a BIG contract at a discount in the resale marketplace, the per point purchase price is not the main thing you have to look at. The most important number in resale is the price that will be necessary to clear ROFR.
On all resales, Disney has the Right Of First Refusal, meaning they review each resale contract and have the option of buying it themselves at the exact terms agreed upon by the buyer and seller. If you price a contract too low, the seller gets their money just the same, Disney gets the points, and you get your deposit back...but no points. You have to start all over again.