Arianna, I've read your post a few times, trying to make sure I am understanding you. Are you asking why someone would sink a lot of money into a DSM, as opposed to a similarly-priced LA that has potential to pay for itself via a business? If so, then what did you mean about the Bernina? That it shouldn't be on a frame when it can do a lot of other things? If that's it, then I'd think you would like it that the Bernina could potentially pay for itself as a LA.
From the responses, it looks like the posters think you are asking why pay a lot for a DSM when you could spend it elsewhere. Which is a different question altogether. Maybe you could elaborate?
Hugs,
Charlotte