I don't know whether this is a plus EV play but these are the considerations.
Except for 49, 50, and 51 you win one bet and lose one for a net loss of 10 at -110 on each bet. Thus your cost is 10.
At 49 and 51 you win and push to return 100 for your 10 at risk. At 50 you win both to return 200 for your 10 at risk. I have no idea what the probabilities of these numbers are but lets assume the chance of each number is 5% just to allow a calculation of EV.
Then net loss is 0.85 X 10 or 8.50.
Net win is [0.1 X 100] + [0.05 X 200] or 20.
Thus the overall win is 12.50 if the chance of these numbers around 5%, which does not seem unreasonable to me. Also note your bet is close to an even money proposition.
Journeyman, a 50 is easier in college than NFL with a missed extra point. BTW what do you think the % numbers should be?