The easiest way to determine the value of anything and the method I use is to do a search on eBay for a similar item, below I have searched for black leather suites, I have also selected used, leather and black from the links on the left-hand side, this search will give you examples of second-hand black leather suits currently for sale on eBay, from fixed price buy it now items to auctions still running at the moment.

But the prices listed on the buy it now items are just the price that people think they are worth, it doesn't mean they are actually worth that price, for example, I could ask £500 for a signed photo of me on eBay but no one's going to buy one so I would be wasting my time trying to sell one, just because someone is asking £200 for a similar item to yours doesn't mean it is worth £200.

What you need to do is check the sold items on eBay, at the bottom of the links on the left-hand side of any search page on eBay there is a link called sold listings, by selecting this link after doing the initial search you will get a list of similar items that have actually sold over the last few weeks or months.

These prices are a more realistic valuation of your item because someone has actually paid this price for a similar item, but please be aware these items have sold to the general public, a second-hand dealer would only pay around 30% of this price, they have a collection, storage, resale, and re-delivery charges to take into consideration before they even start to think about making a profit on any second-hand item.