I disagree with your stance on cosmetics, especially high end cosmetics. When you're paying for premium product it should perform. I have no shame returning something within a reasonable amount of time (immediately to a week). I'm sure there are those that abuse it but if I'm shelling out $30 for a mascara or $60 for a foundation it had better live up to its price.
Yes, but there are TESTERS at the higher-end makeup counters and boutiques. If a customer is unsure about a colour or product, they can easily flag down an MA and have them apply it or advise. I agree - if a product is defective, or causes an allergic reaction - then yes, one should be allowed to exchange or return. But buyers' remorse because the Eyes to Kill didn't meet the customer's expectation that it should be ten times better than Voluminous versus being equal quality? No bueno.
Being an uninformed consumer about cosmetic ingredients - in essence, they don't differ that widely the way clothing blends or materials can between high-end and drugstore - is not an excuse either. Harsh, yes - but I think returning cosmetics (barring the extreme case of an allergic reaction or being sold dried up mascara) is on the level of returning worn-once or tried-on-once undies or a bathing suit.
Agree to disagree.