Hyper Blinker 83 dollars!?

Ok, so I went into a place called custom images the other day and I inquired about a Hyper Blinker for my car. He checks and then busted out with 83 dollars! I dont get it, I have seen them all over ebay for like 8-10 bucks and it seems like a little back transistor that plugs into the existing one in your car. I asked him about that and he said he never heard of it. Whats up with that? Has anyone bought one of those hyper blinkers over ebay where it is just "plug and play"? Is it worth it?