In Supra's defense I have to say that 50 (USD) is a pretty reasonable price.
I'm self employed and the going labor rate (in my area at least) is 50 - 75 dollars/hour for straight labor (in the construction business anyhow, now if your a professional like a doctor or lawyer thats another story).
When you take into account the time it takes to gather up the items, gather the purchasers personal specs, assemble it to those specs and ship it out. I think you'll find that your probably taking close to an hour to do that. Not to mention time spent on tech support ( telling folks how to use it properly and answering all their questios etc etc...
Additionally, it's not uncommon for a contractor to set a minimum price for their efforts. Even if a plumber comes into your house and turns a water valve off it's going to cost you between 75-100 dollars just to have him walk through the door.
So when you consider these factors, it's not really all that outrageous. After all, I can build a house for a quarter of what you could hire someone else to do it for you. If you can build it yourself, go for it. If not you have to pay the price.
Nuff Said, peace M8