For that 150 points, I'm assuming that means you are staying in a savannah view studio. If you go in value season for Disney hotels at the end of August, it is actually 123 points for a week in a savannah view studio, but we will use your 150 points. $16000 purchase price is $106 a point, which is a decent estimate.
Let's say you want to spend a week in a savannah view hotel room. The cheapest rack rate is $550, but let's say you get the 20% discount so it is $440 a night, which means you would be paying $3080 for the week. It's a little low since I didn't take into account the increase in weekend rates. $3080 is a savings of about $2066 off the annual dues of 1013.48 of 150 points. If you save $2066 every trip, that means you break even in your 8th year and start saving a lot of money after that. With ~40 years left on the contract, if you took that trip every year, you would come out ahead ~$66,000.
This math doesn't take into account increases in annual dues, but I'm assuming they go up at a similar rate as the hotel rack rates. Also, your break even point is a little lower if you drop it down to the 130 points you need for that time period (break even in year 7, with lifetime savings of $72,666).