If you want a treadmill but an outright purchase of home gym equipment is an unrealistic option, look into renting a treadmill.
Determine whether you want the treadmill to stay in place or fold for easy storage. A good rule of thumb for space needed is to set aside a spot large enough to fit a twin size bed. You will also want to keep ceiling height in mind. Some treadmills will raise your height considerably.
Determine an amount to spend on rental fees that your budget can easily accommodate. Also keep in mind upon rental there will be a deposit required. Inquire about rental agreements. You may be able to get a lower fee if you agree to rent the treadmill for a certain amount of time. You may also not want to be caught in an extended lease agreement that would be expensive to break.
Contact your local gym and ask if they rent equipment or know of where in your area you can rent a treadmill. Do an online search or look in the phone book for places to rent a treadmill from. This is going to vary state by state and region to region. You may have to drive a considerable distance to find one so check on delivery fees. It may serve you well to enlist the help of friends and family who have a way to haul a treadmill. Make sure they are strong and able bodied, treadmills can be extremely heavy.
Try out the different models that are available for rent. You'll want to be comfortable with your choice. Compare and decide which bells and whistles you really believe you need. The amount of extras on the treadmill will, of course, impact the rental fee.
Ask about the cleaning and maintenance history of the treadmill. It should have received a thorough cleaning between rentals, complete maintenance and have no history of breaking down.
Inquire about any insurance plan and understand it completely. Sometimes homeowners or rental insurance policies can be the least expensive choice. The agency renting the treadmill to you may require that you use their insurance.
Inquire and gain a full understanding of who is responsible for any treadmill maintenance and repairs that may end up being needed. It wouldn't be in your interest to be responsible if a part on the treadmill happens to wear out due to age or faultiness.