What is more fascinating, is this list.
Steelers- 6SB's
Giants, 3SB's
Raiders 3SB's
Bears 1 SB

Total 10 SB's.


Seahawks, 0 SB's
Dolphins 2 SB's
Tampa 1 SB
Rams 1 SB
Cowboys 5 SB's
total 9 SB's.

And, It's evenly split-money does NOT buy success.

Now, when you remove the SB's won buy teams before the rich owners got there-- that removes 3 of the cowboys SB's. Which means it is 10-6.
Don't forget the Packers, which only cleared 9.8 Million (puts them in the poor camp), that is three more for a 13-6 (Since Giants are listed twice, I added the Packers back in.)
So in honesty, being poor in the NFL seems to equate to more titles. Probably because you stick with what you have, don't make a lot of changes, and simply follow your plan-Heck, even the Raiders did that in a way, before owner went nutters.