My question of worth it was regarding buying down points (from 3.5)
When I took out my mortgage, I made the assumption I would keep it for the whole 30 years. (That may not be the case today, but with interest rates so low, it may be.)
I looked at what my total payments would be with the 0 pts rate vs the 3.5 pts rate. The added the cost of the points to the cheaper, 3.5 points total.
If one is significantly better, you have a winner.
If the rates are similar, I'd probably take the no-buy-down deal. With points, you're paying some of the expense up front, rather than over 30 years. If rates drop - which is unlikely, because we're at historically low interest rates now *- you can refinance to a lower rate. With points you've already paid up front for the better rate.
* Although you young people don't realize this, the interest rates now, (before the covid economic implosion,) are being kept low by the government. Obama did this to help the 'recovery' and Trump and his Fed Chair were beginning to raise rates slowly. At this point, they'll probably be kept low for a while longer, but some time in the future, they'll go back to free market rates. And that will surely be higher.