I own this machine, and it works great for garment leather and medium weight veg tan leather. It will easily sew up to 3/8" of leather using up#138 thread. Used machines can be found within your budge, and new for around 1300$. But there are dozens if not hundreds of machines that would work in this application. I think the real trick is finding one that fits your needs, gives you some room to grow, and is easily maintained with parts readily available.
I don't know much about garment making, but if you would like to make things like Purses ,you will want a cylinder arm machine.
I spent a lot of time searching for used industrial foot walking machines that sew leather well, and there is generally not a lot available on the used market. If you are wanting to buy one quickly, you will want to watch the classifieds daily, as they often sell extremely quickly, especially when they sell for a good price. Most likely, you will need to buy new if you are in a time crunch if nothing pops up locally used. New machines are going to be more than your 1000$ budget.