denisse292 wrote:
Not looking for any poor quality Walmart or Target bikes.
You're best bet would be to go to a bike shop near you that sells used bikes and buy the bike that fits you the best.
The funny thing about your original post is that when you described what you are looking for you described poor quality Walmart or Target bikes, but then you included a sentence that states that you are not looking for big box store bikes.
If you are never going to ride for more than 20 miles, and all you want is a cross training workout, then you could get a quite crappy bike and it would serve your purposes without a problem. You would need to maintain a nice bike just the same as you would need to maintain a crappy bike if you want it to last.
I would recommend a fairly fat tired, fairly heavy, bike at the local shop. What you are looking for is what the shop will probably refer to as a hybrid or commuter bike. That will be the cheapest kind that you will find. You'll end up riding quite slow because of the weight and the rolling resistance, but you can get a good workout in that would function as cross training. The downside would only be that you won't be able to go 70% of the same speed as any of your friends that you would try to go for a ride with if they have a road bike. If you'll never be riding with anyone, then no problem.