I have used Aliexpress a few times in the past, never for reps, but I think their payment system ali pay works quite well, and if I remember correctly, the buyer has to release the money to the seller upon receipt of the goods, which provides reasonable buyer protection.
I agree that the price of reps has gotten totally out of control. I still like this site for the knowledge of the sellers, but it is two years since I bought a rep. More and more, I have been buying vintage gens, as they cost about the same as some high end reps. You can buy a good vintage swiss watch for $700- $1000.
I am shocked by the prices I see for reps that I bought 5 years ago for less than 1/3 of the price.