Lord knows I am guilty of using the cheepest parts I can get,being broke all the time--but when it comes to things like ball joints,and other labor intensive to install critical parts I'd rather install ONCE,I go for the ones that look the best built...I dont enjoy doing ball joints on my old 4x4s ,once is more than enough!...ditto for the axle u-joints,I might skimp on the others ,being easy to change,but not the axle joints...
However,I have seen many Moog parts that were not up to their former quality standards that failed in short order in recent years,evidently they too are outsourcing parts from overseas factories,and or re-boxing them...other brands that had good reputations are also slipping as far as quality..
Some vehicles like Dodge Durango's and trucks and GM's with IFS seem to wear ball joints out much faster than our older trucks did too,I feel they didn't use ones large enough to handle the weight of the vehicle..on vehicles like that I'd definately look for the better quality parts...
Prices can vary widely on the same part from different sources too,so it pays to shop around--my friend had to replace a Kia ball joint the other day,and all the local jobber stores would have had to order it in the next day,Auto-Zone did not list one at all,and Advanced and the other stored claimed only Moog made one,and they'ed have to special order one,and the prices ranged from 110 to 150 bucks...its one of those that comes with the control arm as one unit..
He told the owner to try buying it online if he didn't mind waiting,or it possibly being wrong once it came in,but he called one store my friend doesn't do much bussiness with only a mile away,who happened to have one right in stock ,in Beck-Arnly brand (which most likely was a Kia OEM one re-boxed),and he walked out the door with it for less than 50 bucks!...so,the moral here is,it might be a pain in the butt to call EVERY parts store locally,but its probably worth it,if it saves you 50-100 bucks...I often find dealers have parts in stock no other store lists or stocks for the same or less $$$ than aftermarket junk too,so dont assume the dealers prices will be inflated,its not always the case on some things..