Explain potential impact to me as you see it.
When you boil down how many of those students are likely to engage in commerce in Buffalo compared to Amherst, UB is on equal terms with Buff State IMO. Amherst already has retail, food and pretty much everything the city offers right around the campus. I do not see how kids would prefer to spend 45 min on a metro going downtown compared to 8 min to the mall.
Added to that, my other point was for Buffalo to "unlock" UB North, Amherst has to go along. It is going to have to approve a metro cutting through the town. Even if, and it is a HUGE IF, the region would get funding for such a project, Amherst would be calling the shots. While most people here hate Amherst, what they do not see is Amherst really does not care about the city.
Going down to Buff State on the other hand would not run into the same issues of us v. them AND it would actually make the city function more effectively. A B-line from UB north to downtown would do a lot but a V-line from downtown to Delaware Park and to UB South would be a better overall ROI IMO.
The convention business would not benefit from a UB north extension but would from a Buff State. City property value would not really benefit from a UB north connection but would from a Buff State. Overall it just makes more sense.