In my experience i have found solution because locally problem to find some products that are with specifics like parts for tablet, laptop, and other tools, accessories, etc. also skipping abused prices that locally common used for different products.
About the quality of products sure need to know what exactly you are searching for. And if you need cheap products can't be expected high quality. Also i can say that is not the high price that decide that product is good, you can't take like reference.
Need to search for specification of products that you need also to read the specification with details, because in this way you will know what you will get.
Most of the time i use the communication with seller as you go to the store physically
Easy way to make a payment, easy to refund,
When i receive the products like Digitizer, screen, parts for computer, etc.
I use phone like video recorder in the moment when i open the products, also i record the moment of mounting parts. In this way i can prove that everything by my side was correct if some parts fails or are damaged.
In the case when i receive the damaged products. First i start to communicate with seller about the products and usually they will find solution to send another if the proves are ok, if i don't have time to wait for another, they will turn the money back. If not it's easy way to open dispute and upload the photo and video that already recorded and receive money back. Full refund.
What you need more?
I like, I use, they can go forward with filtering of sellers that are not good.