I have a amateur partner too-- I don't directly pay her money to dance with me (but have to pay in other ways), I get lots of grief, aggravation, arguments, late lessons starts, unwilling to practice, and lack of teamwork. We do have our moments when everything comes together in competitions. I even pay for more than my share of lessons, comp. fees etc. and have much more down time trying to figure out what is right or wrong. She is stressed at work and has little money for dance lessons and other fees, but she is worth keeping and paying some of her extra expenses since we have been dancing together for years and she is a wonderful dancer. However, she is 3 times harder to progress with than my Pro/Am partner.
Any type of dance partnership is a team and you are paying out in one form or another. Even paid business employees are part of a team and should be treated like a partneship--even though they are paid a bonus or salary. I have never heard of paying a Pro/Am partner a bonus in the form of money.
You guys underestimate how hard it is too find a good dance partner--even a suitable Pro/Am partner that you pay to dance with you. I have about 15 other female pros to choose from to dance with, but I chose my current Pro/Am partner because I liked the way she danced and she is 5'10" tall (I am 6'2"). I has been very hard for me to find a tall female dance partner. Just because someone is a Pro doesn't mean you can dance well with them. Some pros are better at teaching and shouldn't even bother dancing Pro/Am. Probably only 5% of the dance population compete and probably a small per cent of dance Pros are suitable for high level Pro/Am dancing. I had the hardest time when I first began dancing and used social dance teachers as coachs. I was a beginner and didn't the difference-- I just didn't know that there was a higher caliber of competition dance teachers.