Supplier Negotiations

Is it okay, or how do I bring up that I found their product on 1688 for very cheap while they are charging a lot more for it on Alibaba. They will sell a part for .29 in China but charge me 1.88!

Please let me know if this is ok to bring up in negotiations (In a nice way of course) . Thank you.

Also, how hard do you drill your contacts for a better price?