Great advise there! I only have a bit to add.
First of all... I don't know you, so I don't know if running is a new idea to you, or if you have been doing it for some time. If it is totally new, you may want to consider going to a gym for the first few months of training... just to be sure you are going to keep it up. It would be a shame to spend lots of $$ on a TM only to find that your (fill in the blank with a body part) ____________ can't handle the running.
Second of all, I agree with what the PP said about WHERE you are going to put the TM. When I got mine, I had to fight with DH about NOT putting it in the basement. I knew it wouldn't see any use down there, no matter HOW determined I seemed to be. Who wants to go down to the dark, damp, cold, lonely basement?? I put mine in our bedroom and I haven't regretted the decision. Yes, occasionally it gets used as a clothes hanger (I don't use it every day and I run/exercise at the Y several days a week), but it is still right there, handy whenever I want to use it. I can watch tv or a movie while I run/walk. And the kids can use it whenever they want and I'm SURE they wouldn't if it were in the basement. Mine is a fold-up kind and I have had it for many years without trouble.... admittedly, it has gone through periods of "rest" over the years
Cup holders are very handy.... especially if they are deep enough. One thing I would like that I don't have is a lighted display. Sometimes I run early in the morning while others are still sleeping. They can sleep through the TM noise and the tv noise, but I don't want to turn on a light and then I have trouble seeing the display (I like to keep an eye on my mph and such)... so I run with a penlight in my hand.
THis is a big time of year for people buying exercise equipment, so you may find good sales at the bigger stores. That said, there may be less used equipment available on Craigslist and Ebay, due to increased demand. If you want to buy used, wait a few months, until all of those New Years resolutions have been broken and people are trying to unload their new equipment.
Good luck!......................P