That's really what I've found. If you are determined to DiY, then you can certainly achieve excellent results.
I've built a screen, which took several evenings to do a good job on, and cost me over $100 in materials, including a true velvet border.
Between the time I invested in it, the difficulty I would have had breaking it down, and the expense of parts, I would never do it again.
I recently picked up another screen for testing. The Silver Ticket 110" screen from Amazon for about $250. It easily is as good as what I built myself. I can break it down, move it if I need to, and it went together in about an hour or so. No complaints on what I got there.
Not trying to discourage you if you want to DiY, but just inform you that you can get great results from cheap screens and that DiY solutions aren't always that cheap overall for good results.