Part of the issue you've experienced is the mentality in China: chabuduo (it's good enough). What if you went through six saws and they're all junk, but the seventh and eighth are going to be pretty darn good? Is that good enough?
There are standard steel grades, and Chinese steel grades that approximate actual steel grades but are "good enough." STIHL/Husqvarna plastic is very well engineered, Jinhua Farmertec Import & Export Co. Ltd. plastic is flimsy and brittle by comparison. You get what you pay for, which isn't necessarily bad dependent on the use.
STIHL/Husqvarna/ECHO make solid saws that are pretty miserly on fuel, light weight, and reliable. That reliability and brand establishment costs money, and the saws aren't "cheap" but are "reasonable" for the quality.
Jinhua Farmertec apparently gets parts from "whomever" has them cheap at the time, and generally they're mostly reliable. The carb might require frequent tweaking and dropping the saw might break a cover, but replacements are cheap. There are companies that own a fleet of blue saws and have a full-time repair guy to keep them running, they feel it's profitable to run that way.
It really comes down to how valuable your time is and how important the job is. If you're planning on doing a job and your saw goes down 4 times setting you 2 months behind schedule due to parts replacement, does it matter to you? Then again that third saw you bought might run great for years, that's the gamble you take.
I think for the money, you have to realize you're probably going to have to shotgun some parts you may or may not have on hand into Blue Saw #3 to keep it running, costing you at minimum time and possibly more money, which you might be fine with. Given the size of the job you have other people might buy one saw (maybe used) and sell it when they're done with the job, or maybe move on to another job.
I don't know that Chinese saws make sense financially. They mostly work, at least for a reasonable length of time, so for a small job you've a small investment. A name-brand saw has a much higher probability of avoiding issues and can be sold to recoup most of the investment, so does either saw put you further ahead? If your time is worth something, a name-brand saw seems to make more sense than a clone, but if you like spending time fixing saws, then maybe the blew ones are just fine.
