It's just a plain fact that the all time #1 best place to get the unbelievably best deals on Authentic MAC Makeup Lots is online. But do you really know where to look and do you also know how to spot and avoid the knockoffs and counterfeits?
Here's Something You May Not Have Known
The first item of interest you may not know is that there are now other online auction sites besides Ebay. Sure Ebay is the biggest on net but none the less if you can't find what your looking for there in the price range that you had in mind, then head on over and check out some of these other sites.

Check Some Of the Cosmetic Sales Websites
Of course there are always the independent cosmetic marketing websites that are worth taking a look at. But remember that they're not all alike, so some will have better selection and prices than others. Also there are a few other things that you will want to be aware of when your browsing sites.
Learn To Spot Fake Make Authentic MAC Makeup Lots
That is that sites based out of Asian countries and most particularly China, all have a well earned reputation for passing off counterfeit makeup, perfume and fashion accessories as the genuine article. Sure the prices are rock bottom but so is the quality of the crap that they sell.
Don't Be Shy About Asking Questions

Always make sure to check the contact information on any website to see where it's based out of. Also never believe any of the BS stories that they'll give you that explain why their product is so cheap. Ask them if they can email you a close up shot of the back label so you can check it for spelling errors.
Beware Of Prices That Are Just “Too Darn Low”
Chinese made fakes are notorious for spelling errors and another thing to check is the bar code. Most knockoffs will have a printed on bar code, while Authentic MAC Makeup Lots will always have a bar code sticker. Hey! If a price is less than wholesale, then you have to ask yourself “how are they making any money unless its a fake”?