If your looking to get it it the platform and your debate is between a “gently used” pre-2013 Chinese rifle and a base model SAI (apples to apples IMHO), get the Chinese one.
Generally speaking, I do the same “standard” stuff to a base model SAI to a Chinese rifle. The biggest difference between the 2 is the parts like rear sight, gas cylinder and flash hider. The SAI parts will be good. The Chinese parts likely won’t. It is very very odd to find “square” or “true” keyways on the Chinese parts and the Chinese rear sight is only good for “set and forget” because as soon as you move the rear sight it won’t return to where it was.... the SAI parts will be more-or-less square /true and the rear sight will work.
The Chinese rifle can be had for under $650, the SAI will cost $2000. The value of the parts that will likely need replacement will be under $400. Not that the Chinese parts don’t work. They do, and they will be just fine for casual plinking. The only time those parts will start to hamstring you is when you decide to do a bit more than 12” steel at 100y shooting....
Telling someone to “look at an LRB” when they ask about the M14 is like telling someone to buy a New BMW M5 when they ask about “What car should I buy?”. There are lots of options out there right now that are reasonable and less painful on the pocket book. Now don’t get me wrong, I have 3 LRBs, and I love them all. But my “go-to” gong ringer at 300y and closer is a chi-com with some upgraded parts....
YMMV
John