You've asked me how in the world to make this all work for you. You're not lucky enough to have a Health Reimbursement Account at your place of employment. You're living from check to check. You don't know how to make it all work and it looks totally hopeless.
Here's a relatively simple answer that just about anyone who is truly motivated, and isn't just using the above as an excuse.
No. Wait a minute. I'm serious. Do you have 10 hours a week? Like, give up CSI for 3 months? Or maybe you're an ESPN addict. Give up Canadian Log Rolling Championships?
10 hours a week x $8.00 x 12 weeks = $1000.00
Since this will have almost no impact at all on your taxes, have them skip taking them out. You can do that with a second job. Really.
Here are a few really good treadmills for $1000 or less, with free shipping from one of my favorite places to get athletic equipment:
All three are name brand with free shipping (available as of this posting) and should have all the normal features most normal people really use, and should last a very long time. I have a Costco Treadmill with probably a thousand miles on it in the five years I've had it with no maintenance other than cleaning the belt and deck surface with one of those microfiber towels (don't do this if you're clumsy, I'm just sayin').
SO no more excuses. What's your future worth to you?