The build for buddy system:

A kit such as the Sig Four Star 40... the person who wants you to build it buys 2 kits, all the covering and glue for one kit and the builder's fee is the second kit. Scrap covering goes to the builder, but if there's more than 1/3 roll of a single color... it goes to the person who bought the kits.

This works GREAT for someone who likes to build planes. And can act as a guide in appropriate compensation when a FRIEND builds a plane for you.

************

Pro building service... Too expensive to mess with really. Again using the Four Star 40:

Passable speed building will take appx 15 hours of labor. That's about $150. An average modeler's quality workmanship will have the builder spend closer to 40 hours on the plane... $400. A true professional quality job will have up to 80 hours of labor.

And the Four Star is a SIMPLE kit.
*********

Assembly of an ARF and installation of the radio can take over 6 hours... for a simple .40 size trainer. There are some ARF trainers out now with the radio and engine already installed... and can be prepped for flight in less than 2 hours. (not counting charging the batteries overnight.)

More complex ARFs... can take 30 (or more) hours of preparation and modification to meet the requirements of some modelers. Even though I had my Fokker Dr1 ARF flying 3 days after I bought it... I continued working on details and now have over 50 hours of work in changing the model from the original ARF.

******

If you are contemplating oing this on a semi-professional basis... you'll find you have to charge too much for the customer to afford, or it won't be worth your time.

If its for a friend... Just ask him to buy you a can of gas, for assembling a simple ARF.