I had found this post when searching the FAQ, and it reiterates what you paid:
There’s also a mention in the FAQ page that says that they’ll sell the parts, but it doesn’t say when. What’s odd, and I guess it’s because of the “competition” it states there won’t be a manual sent when purchasing the tube directly…Here’s another update that supports that they’ll sell replacement tubes:
It also states that that’s the pricing within the US, so I guess we don’t know what the EU would cost. May be something similar, but with you paying the additional shipping costs, or maybe they’re saving the pricing of the tube and parts for when someone like you does need a replacement. From what I remember, there was a possible issue that selling the tubes directly may have an impact on the alignment, but that might just be my memory from questions that were never officially answered, so take that with a grain of salt.