Anyone have a treadmill?

I have become very frustrated with myself lately...

Before our wedding, I was doing so good with eating healthy and exercising. I was in great shape and was very confident with myself. But after the wedding and honeymoon, I haven't been as good. I haven't been good at all. I have fallen off the "Paleo diet" wagon and haven't been exercising at all. I no longer feel confident and have noticed that the weight I lost for my wedding is slowly coming back. But the main thing is that I am no longer happy with myself as far as diet/exercise goes. I didn't diet/exercise JUST to get skinnier and look great for my wedding, it made me FEEL great too. Part of the reason for my lack of exercise is the season. It is dark when I wake up and dark when I get off work. How am I supposed to run when it's pitch black outside? I have contemplated getting a gym membership, but they are so expensive. Especially when I will probably just run on the treadmill and then do some squats, pushups, sit ups, and pushups. I love running outside and plan to start again as soon as it is light outside when I'm home from work. My parents have a treadmill that they don't use anymore, but it's pretty old, so I'm not sure how much longer it will last. But maybe it'll work for a little while.

I've also been thinking about training for a marathon again. I trained with Team in Training 3 years ago and ran the Honolulu marathon. I injured myself during the 20 mile practice run 3 weeks before and had to walk during parts of the marathon. Because of this, I would like to try to run in one more full marathon...just to say I ran the whole thing. And I'm thinking now is a great time. Training for a marathon is a big commitment, but we don't have any big plans this year, so I think now is a good time. But it will depend on whether I can find a treadmill or get a membership to a gym to run on the days I cannot run outside. And I'm hoping to find someone else to train with. Ryan said he would run with me on the shorter runs and ride his bike next to me on the longer ones. But it would be nice to train with someone that I can run in the marathon with. Charlotte said she would be interested, so hopefully we can find times on weekends/weekdays to run together. First task...get a treadmill or gym membership.

Anyone have a treadmill they are looking to get rid of? Or know of some great deals? I would REALLY appreciate it!