I've been given several MAC samples. I was once given a couple of unsolicited skincare products to try and when I was looking at foundation I was given a full sample pot and some primer to test out (I subsequently bought both). When I went back to get the foundation, they were out and gave me a second full sample pot to last me long enough to order it online. I would not ask for a sample of pigment nor any colour product - I'd try them in the store. Foundation is different; I want to see it in different lights and be sure it doesn't break me out.
I was recently given a couple of testers. I wanted to make a quad so I swatched and selected colours with the MUA. I didn't know two were discontinued since the testers were there. They were sold out of both and the MUA simply pulled them off the display, handed them to me and told me to make them disappear. I purchased the quad pallette and the two other refill palettes. I was very surprised at that (neither of them even had a slight divet) and hesitated, but she assured me that it was fine and that they couldn't be sold anyway. I've purchased quite a bit from this particular MUA and she certainly knows that I'm a regular.
I was a bit squicked out at the thought of how many people might have used the e/s, but I scraped off the top layer when I got home, depotted them both, and am happily using them. That was very nice of her, but it's not something I would ever ask for or expect.
I woudn't hesitate at this point to ask for a foundation or skincare tester, and I can't imagine that that type of request would be declined (unless they didn't happen to have pots).
I don't think I'd ever even dream of asking for a pigment or lipstick sample, just due to my own shyness & the lack of customer service.
