What Do You Consider $ Well Spent on Home Excersise Equitment?

The only thing well spent to me... is anything that you WILL use, and make use of. Regularly.
Even if that means, using a pair of walking shoes.

For knee problems... your Physical Therapist will tell you WHICH exercises to do... per your condition. Not every person, with a knee problem, will be able to do the same exercises. It is NOT, a one size fits all, type of exercise routine. It depends on your particular, knee condition.
So, keep that in mind.
If you do something that is customized for someone else with a knee problem, that does not mean, you can or should do that same thing. Or it can make it worse.

I only say this, because my Mom recently had a stint with Physical Therapy, for her knee. For a Meniscus problem. But, the Therapist said it is not her meniscus, it was something else. She was doing exercises her friend was doing, per her friend's knee problem & THAT made it worse... -because my Mom's knee issues, were not the same. Thus, my Mom's Physical Therapist, was able to correctly tell her, what exercises, SHE should do... and cautioned her that doing whatever exercises just because someone else is doing it, is not the best. And not, wise. You need to go according to the knee problem that YOU have.

Well... if I were motivated enough, I would say that the Total Gym was $ well spent. For my husband it is. He loves the thing. I like it alot, just don't ever make myself do it. When I do get motivated and spend time on it, it works. And works well. My kids even use it sometimes.

I have a treadmill and I love it! I like that I can vary everything from speed, to distance, to incline. I just love the versatility!

Elliptical. I loved mine & then hard times hit & it's one of the the things we had to sell. I still miss it. We are doing better financially now & it's my fav @ the gym.