On eBay you can often find make up that was sent to magazines or bloggers for reviews and then sold on, usually brand new as they were only photographed and not even tested. They usually come with a sticker on the bottom stating that they are review items, but usually in their normal packaging, so they look just like the product you would buy in shops. And who cares about a little sticker when they can save several pounds? I have many Mac (and other high end incl. Clinique) items that I bought on eBay and are marked as samples, including lipglosses, lipsticks, eyeshadows and blushes. See photos below.
3. Trial size items
I use very expensive skincare products (Guerlain's Orchidee Imperiale range) and am of course more than happy if I can save money on them. One way of doing it is buying trial size items. You know the little tubes of creams, etc. that you are given with your purchase to try out. Guerlain Orchidee Imperiale Exceptional Complete Care serum costs £230 per 30 ml, which I have never paid for it, I would be mad to, when I can buy 10 little tubes (3 ml each) on eBay for often as little as £30-40. Sure, I don't get the fancy packaging, but then again, no packaging is worth paying £200 for, right? ;)
Now I have mentioned buying from eBay in every one of the points above, but I wanted to give it a separate mention, because you can find brand new items in normal packaging at a fraction of retail price as well, you just have to keep an eye out for them. If you don't mind it if something's used, items that have been tested sell for even less. (Although eBay is now not allowing people to sell used make up anymore, not that it stops people, lol.) There are fakes on eBay, especially high end make up (not just Mac, I have seen plenty Chanel, Guerlain, etc. fakes), but if you do your homework, you will be fine. I have bought over 500 items on eBay and only bought one or two fakes myself (and managed to get my money back anyway thanks to Paypal).
5. Sale / reduced items
And of course we all love sales, and you can always pick up some nice items at half price or less. Unfortunately that often means waiting for months and possibly missing out on certain products, but I have picked up a few limited edition items at half price that I never thought I would, including Guerlain's Meteorites Voyage Powder!