if you enjoy building and plan on building your own kits initial run up cost can be expensive,after that you can build them cheaper if you are a prudent shopper.a lot of building supplies,things like stick pins,table cloths,cardboard sheeting,measuring tapes,yardsticks rulers,and a lot of other materials can be bought at local dollar stores.i buy white glues and epoxies,spray paints from the hardware stores.my children and i do other woodworking so i can justify buying things like scroll saws bench and sanders.if you can find the kits that include most of the things needed like control rods fuel tanks clevises.you can build them cheaper than an arf.the last kit i built was a pt 60,and i kept a list of supply cost.i got the kit for $80,three rolls of mono-coat,and pint of glue one bottle of med and one of thin ca,a fuel tank and three light wheels with clevises,fuel tubing,sandpaper three grits$75 and some change.$155 total and knowing that my daughter and i built it and it has IMO better quality than i could buy as an arf.and i get to spend time at home with my daughter she is my building bud,it took about 5/ 8 hour days to get the kit built and covered,and the enjoyment out of doing it.the look on my daughters face when we took it to the field to fly was priceless.i think the labor part doesn't count if you enjoy building these things.if you were to put a price on the labor or tried to make money at building models by hand you would starve.startup basic building materials i would estimate about $300.if you build about 3 to 4 kits you would break even as opposed to buying three arf's.i build 60 size planes so i figure arf's cost $200 each.i think that scratch building might cost a little more.the pleasure i get out of this hobby with my family and going to the field to be around others that enjoy it is well worth it to me.the cost of building bigger/smaller kits would be proportional to what i have priced,if you plan a budget.you can spend a lot more depending on extras......