1
 I want to know is there a way or plugin to set the following rules:

one product can only allow purchase 2 per customer. For example: Customer A can buy product A for qty <2, after payment Customer A cannot buy the product A.

So it is not only restrict for product A only set for qty maximum to 2, it is also can check for Customer all order can only buy for product A for 2.

closed as primarily opinion-based by Marius Feb 14 '15 at 12:15

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.