I get asked this question at least a couple times a week. The most important factor are, do you have a sentimental attachment to it? Is it something that can be replaced down the road?? How long will it take me to have the funds to get redeem it???
If you item was passed down from someone in your family, then pawn it and make sure you set aside some money each week so you can pay it off. If you bought a Rolex watch say for 5000 and you need money now, sit down and try to guesstimate how long it will take you to get it back. If its more than a couple months, then you might want to sell it and buy one again down the road when you can afford it. The interest can add up quickly and end up costing you more in the long run.