I belong to Powerhouse Gym on Hayes, south of 14 mile in Fraser. I paid my membership in cash. They have classes there too that are included in the membership(yoga, zumba, kickboxing..etc). The equipment is all up-to-date.
Have you tried Planet Fitness just off the 696 service drive in Warren? I drive by it all the time and it says $10/month. You might want to call and see if they'll do cash. If you pay up front, most places will let you do that.
I just joined Bally's, it's very affordable (if you say no a few times at first), i got 25/month, no contract, nothing down. Not sure about cash but you could ask. There are are a few locations on the east side, one is in Warren.
Re: NBR - need a gym rec