You could dope them by brushing on liquid crazy glue. I have a 37 year old row boat I doped up with liquid crazy glue, and people swear it's plastic. I would never do this again, the piece was on a stick, and I did it outside. It stunk so bad, I could not take it into the house, but 4 days outside, and that was gone. I then pained over it, and I have actually sailed this 9" boat down water tanks 100' feet long x 6' wide at a place I used to work at. There was a massive floor fan at one end, and the little boat, after a few trims, sailed smartly, and the water did not effect it. It is the oldest model I own. One of the Balsa side seats fell out, when my wife was cleaning, and I think she swept it up. I should re-do it, and make a new mast and sail. My sister has the first one, with a wooden deck, made out of Popsicle sticks. That one is around the same age, but is a Catboat. My sister treasures it, and has taken much better care of it than I ever would.
You damned right those models are expensive, and yes, they look it! If you think how much a mold costs to make a plastic one, with all the modern machinery, about that same amount of time, but mold is probably in the million dollar range. Of course, it will pop out a million models, but it won't pop out something like what you made. Something always get lost. It takes a fine plastic modeler a lot of sanding and greebling to bring a plastic models to life, and you're already there!!