Mike,
Haggling is so simple, all it takes is the will to save money. You have to be prepared for the difficult sellers. The ones that are firm with their price. Unless it's a good and fair price. Yet, $65 for the small HOB refugium is not a bargain. $40 would be.
Again, most people hear the price and instead of asking for a better deal, they go "oh, ok, lemmie think about it". As far as I'm concerned, they're not ready to buy, or don't know how to haggle.
When I want to buy something, I ask the price and then give my lowest offer (unless it's a great deal to begin with).
I did that with the guy that sells the Envy Orange zoas and he didn't even respond to me. I can't help but think "knucklehead!". If he was a serious seller, he would'v come back with a counter offer. I think he wanted $250, so to come back with $225 and then we would go back and forth until we had a deal. FYI, I started at $100.
Anthony,
Dogs and Cats will never live in peace.

Don't go crazy with this tank, just do enough to make it functional. Make your mistakes now so when the larger tank comes, it'll be more seemless a transition.