I am selling the same thing and had the exact same thing happen to me about 6 months ago. You will not get any answers out of ebay. But this is what I found out...
It is a site-wide investigation and supposedly is for all sellers they pick and it is supposed to be random. They will not communicate anything with you about this - it is a safety and trust issue.
There was an article in the paper and on CNN about a month ago about a huge ring arrested for stealing high-end cosmetics. So they figure if you had purchased any of it (I haven't and you probably haven't either) that they will limit the amount of stuff we can list. That is the way that I understand it.
Anyway, I purchased my cosmetics and have too much invested to only list a few here and there - so ebay has forced me to go elsewhere to sell my product.
I have listed my stuff on my own website on ecrater. I did this the last week of December and I now have almost 600 items listed. There are no fees and ebay gets no money on the sale (unless the buyer pays with paypal-at least no Final Valuation Fees anyway).
It was easy to set-up and I had my store open within an hour. My sales have been good, the only drawback is that you have to promote your store where on ebay, they do it (but we pay them big bucks to do it).
Hope this helps.
-Laura
Wholesale Outlet Warehouse