One thing that may work - Check other geographic areas. I started looking at gyms a few years ago … for the first time since college. Although Silver Sneakers was an option, I wanted to check out everything that was available. A very nice Lifetime near me was recommended, but their rates seemed high. A Lifetime in a southern suburb (in SC) had much lower rates. Even their reciprocity rates were lower than the base rate in Charlotte. I ended up going for a much cheaper gym ($10/mo), but I don’t need hydro-massage, spin-in, spin-out, or spin-the-hokey-pokey and other features.
If you’re looking for a better ROI, maybe check out properties with some acreage. Give each kid an acre, half-acre, etc. Ask them to develop it, farm it, make it pay for itself, or anything you want. This will not only be a wonderful, educational exercise for your kids, but will also allow/force you to spend QUALITY time with your kids. One of the the side benefits is that none of you will need a gym, Jovi classes, or Slimfast spinners. One other side benefit is the value of the land will probably increase - if not from the improvements of your family, then from time.
Please don’t take the above alternative as a slight, because that’s not the intention. Looking back, one of my few semi-regrets in life is devoting so much time to financial security/independence while my kids were growing up. It’s wonderful now, and I can spend unlimited time with my adult kids, grandkids and almost great-grandkid, but it’s not the same. I’m very fortunate that my wife did an amazing job with our kids, and they’re self-sufficient, but still …
ETA: I’ve been told that once becoming a nonagenarian, you won’t need a gym, because in addition to your regular work, you’ll get most of your exercise shaking your head in disbelief.