I sell second-hand items online, so have been on both sides of the fence when it comes to negotiating. The number one tip I would give is to always consider th

I sell second-hand items online, so have been on both sides of the fence when it comes to negotiating. The number one tip I would give is to always consider the person you are negotiating with (note: "person" != "business") and try to reach a win-win. Make their job easy and maximise their profit/commission. For example, if someone messages us on Facebook with some links to our eBay listings and asks if we can do a better price, the answer is always yes. We're happy because we don't have to pay eBay's cut of the sales (around 10% usually), the buyer is happy because they get a discount. If they're buying multiple items, even better! We don't have to pay for 5 separate lots of "free shipping". Same thing when you pay a tradesman in cash. They "forget" to enter your transaction into their accounting system (no tax!), you get a better deal. Not everyone would consider this ethical, of course, but it's the same principle of tit-for-tat.