I started out with a Makita mortiser, a 10" circ saw, drill and a bunch of hand tools. It is absolutely viable to cut frames that way if you are a solo operator. I think that a good framer knows how to get the results out of what they have. The tools don't make the quality(but sometimes they do help). A Makita mortiser might make perfect sense for your situation. The one downside to the German mortisers is that you have change out bars for 1.5" and 2" mortises. Therefore it makes sense to own two so you don't have to keep switching. If there are a few guys in the shop, this will pay for itself quickly. In your case, probably not.