When you have those low FCS, PRT, UltraPower prices right next to Monroes and KYBs, yeah I would have a lot of questions too.

I suspect a lot of parts store and private brands probably source from the same manufacturers too.
Here were a couple of quick searches I found on FCS, the main complaint seemed to be stiff when the weather gets cold. For the price it's worth a try for those willing to experiment or selling the car. Although personally I have stuck with Monroe QuickStruts assemblies or OESpectrum plain struts, as Monroe offers lifetime warranty even for normal wear and tear while other brands don't. You only need to buy one set and they'll last the ownership from then on.
Regardless of that, the important thing is to pick the ride that you like, or it won't be worth it in the long run.
The Corolla is going strong at 142k miles. Runs like a dream and honestly, outside of routine maintenance costs there has been no real expenditure on the car (except for all the mods I’ve been doing on her). The suspension on all 4 corners is original Toyota. The boots are torn to hell, but I...
www.toyotanation.com
Has anyone had any problems with the fcs struts (if used them) after installing with the tires rubbing the bottom of the spring plate? Or why would they do that because the original ones with 160,000 miles i replaced never rubbed the tires.Im on my 2nd set on the rear same thing
www.toyotanation.com
Here was a discussion on budget brands on the 'Rolla but is applicable in general:
I have been down this path before, but figured I'd see if this has changed but has anyone found any quick strut that is solid besides KYB $400 for 4 corners. Usually, the offbrand assemblies result in a really weird lift, or last less then a year....
www.toyotanation.com