What is the difference

I would like to try Royall Lyme, which seems pretty simple, but I look and it breaks down like this:

Lotion/splash
natural spray
vetiver

So, what is the difference and why can I buy it on ebay for half the price of buying it from their or anyone's website

Watch the size, somtimes they show the large bottle on e-bay but if you read, it is actually the 2oz sampler!!!!
I personally like their splash products....