I pay a premium for Prusa because I like their philospohy of making as much of it as possible in house, and their general openness, not just in code, but in how their business functions.

My first 3D printer was a Makerbot Thing-O-Matic. I'm very willing to spend if I think it will benefit the entire ecosystem I'm interested in.

Also, with Prusa, I get to feel like I'm DIYing it, but with great and detailed instructions, and an all-in-one parts sourcing. They are also great at supporting their devices after the fact, which is sometimes necessary, because they often come out a little too hot.