You can get away with 2, but you wouldn't be able to supplement everyday. If you did, you'd quickly build up a tolerance, and they'd both stop working.
If you're the type of guy that has an off day here and there, 2 may work for you. You'd just have to make sure you took at least a week off between doses for each supplement.
If you've got a severe case of low T, you'll be better off if you have more than 2 on hand if you can afford it.
If money is a problem, work with what you have and focus on all the other things on this site, like diet, and exercise.