I'll jump in here as well. I've built many kits and assembled a lot of ARF's for people for hire. I let them know right up front that I will do a maiden flight on the plane to ensure that everything is working right, and to make any adjustments that need to be done. If a customer doesn't agree to that I won't put the plane together, plain and simple. Why would I insist on this? As was stated above, just putting a plane together is only half of the battle. It's not considered a safe plane until it has been tested and any adjustments made. I test fly the plane because I want to give somebody the best product that I can possibly give. But there is another reason as well. The builder/assembler is responsible for that plane, and the quality of it. If the plane is given blindly to person and it crashes then they can say it was my fault. As somebody mentioned above, if it's been test flown they can't blame it on the plane.

IMHO you got a great value for $300 and you had this done by a shop that cares about their customers a great deal. I would be wary of the one that only wants $100 to assemble it.

Ken