With the amount you spend every month (8K) you can ace the sign up bonuses. You can either completely eliminate the $15K per year in airline expenses, OR, if award ticket redemptions turn out to be tricky for you (there is a learning curve and some quirks to award bookings), at least get 3x the points for the dollars that you are already spending on airfare.

In truth, with your expenditures, I think, with very little effort and a little strategy, you will be VERY pleased with the results you get with joining this hobby.