Tango + was about 3 times as much on the same flights.
$950 vs $2500 didnt seem worth 7000 miles
There dont seem to be any promos with rival airlines.

Used up all the eupgrades (have 11 left, cant use them for upgrades on Tango plus for this flight, need 17)

The 50% tange miles will help go over the next threshold anyway so no concern there.

I had dates in mind 13-22nd, no other flights came close.

Brendan.y : What greater problems may we YYZ folks have?

Driving to BUF is too much effort. not worth the savings usually