The first question is: "if I pay you cash, whats the best price you can do?"
Back in my LFS days I was known to counter such offers with a substantial price increase

Not sure why anyone would go through that mission to sell the fish for $100 and only make a $15 profit on a $75 gamble.[/QUOTE]
It's simple marketing, and yes marketing costs money...making this actually a cheap marketing move. Simply, it's an iconic high value fish that is in reach of most aquarist when sale priced...it's a hook that will bring more customers into the store, cause more customers to talk about the "great Purple Tang I got at XYZ LFS for a great price", bringing more customers into the store. Said customers likely buying more than just that sale priced fish...the more than being your profit

Now I'm cheap, so the above LFS marketing lesson is available for the price of a beer or a frag

Lol, welcome to business Jovany......if you can't beat them with price, you gotta beat them with something else. The business triangle.....quality, service, value.....pick the 2 you want to be/have.....but you can't be all 3
In my business, it's the first 2:beer:
x2
It's a cut throat business, and at the same time there are also some really good people in it. Enjoy it, but don't expect to make lots of money.