Last summer before the crazy set in I purchased a used Kinetic Road Machine off CraigsList. I got my monies worth out of it, $100 plus a tire. I put 3300 miles on it since November, 7 months of training. That translates into 9 1/2 days on the trainer 24/7. This is much more than i usually ride outside in the same amount of time frame.
If I had it to do over again I would get a Wahoo Kikker Snap as another poster recommended. While some individuals seem to be able to live with the tedium of indoor trainers I had to resort to using Zwift. The fact that there is a very big possibility that you might decide to take indoor training seriously makes it in my opinion a wise move to get a smart trainer so that you have the flexibility to use 3rd party applications to find relief of the lack of mental stimulation and physical feedback.