I’ll let you in on one of my secrets to finding deals on cables, A/V accessories, and computer stuff. Check out monoprice.com. I’ve ordered a bunch from them lately, and I have been very impressed with both the quality and cost of the products they sell. When you check out their prices for cables, you will be blown away if you are used to ordering from other online retailers. Their prices are really cheaper.
I also order a lot from Amazon and Newegg, but if Monoprice has the item, they are almost always cheaper. I recently bought a 100′ VGA cable for $31 and a nice projector mount for $26. Check out their site and see what they have to offer. They also offer good quality XLR cables and adapters.