RE: Nitro models planes
ALL ARFs are "builders ARFs". Some just require more "builder's art" than others.
I've been pumping out ARFs for the last year at the rate of one every couple of weeks. I've seen mostly the more popular mfg's but have assembled a couple of bargain "you get what you pay for (or not)" ones. I've yet to build one that I didn't modify something that needed it.
Back when everyone built from kits, plans or scratch, everyone expected to learn from each model. They learned what wood worked where, how thick it really needed to be, what didn't hold up day-to-day.... etc etc. Noone with any experience built their next plane without looking long and hard at it's design and construction details. Everyone looked for weakness as they built. As far as I've seen in the last year building ARFs, that hasn't changed one bit.
I've yet to build even the most respected mfg's ARFs without having to fix what I'd consider a flaw in design or assembly. I just dissected a "perfectly good" airplane to see what else was wrong with it. It wasn't worth bothering with anymore. I'd discovered that the aft fuselage sticks were all balsa. No way the sucker was going to live very long if I continued to fly it the way I chose to fly it. The top sticks were already compressing under flight loads. And I discovered a couple more "toy mfg making ARFs now" problems. And the ARF was from a respected top-name ARF mfg.
Expect to learn from every ARF you assemble. And what you learn, apply to the next one BEFORE you finish it. Things haven't changed much since the old days before ARFs.
The more expensive ones simply have a higher probability of being flaw-free. The cheaper ones have a higher probability of having flaws. Heck, some of the cheaper ones look like they were made with the flaws on purpose to test your patience, or convince you to buy some other brand next time.