Before I start throwing out websites and reviews, I figure I'd better post my spiel. I give this to people on DJForums.com who have a question about the gear they should get. These rules and lessons have been the basis for the way I've made my own equipment purchases.
Do Your Research: Go to a website like GuitarCenter.com and narrow your search for what you're looking for. Then copy down the names of each one of those companies, and go to their respective websites. Take a look at the in-depth specs of each of their products that sounds interesting, and make a list of every SINGLE item available to you, whether or not it's in your price range. Then cross out items from your list as you go through their specifications and find that they may not be what you're looking for. (No piece of equipment is perfect, but you should prioritize your goals and interests.)
Once you narrow your list to 4-5 decks, go through GC and check their reviews. Then go to Google and check its reviews, then go to YOUTUBE and check both REVIEWS and DEMOS of the decks.
^^^ This is the step I left out when I was shopping around for my Numark X6. I checked youtube AFTER ordering it, and found that there were some issues with the mixer that I hadn't though about.
Get Hands-On Experience: If you can, go visit a Guitar Center or other retailer that has a demo model available to customers, and try it out, see if you like it. Even if you can only fool around by pressing the buttons and moving the table. Pick it up, check its weight. This may narrow your search to 2-3.
Come Back To Us: And offer a comparison between several decks. Of all the members here, you'll find SOMEONE that's used each piece that you bring to us. Do more research after that, make sure you're Satiated, a master of all of the unit's specifications before you choose definately.
Wait For A Deal: It's easy to get a wad of cash and spend it all on brand new equipment. Instead, wait for a good deal on GuitarCenter.com or another site: check E-Bay, Amazon, other retail outlets. Using this method, you may find that you have extra cash to spare, or maybe that "Just-Out-Of-Reach" item is on sale within your budget. Go for it!
I know guitar Center has sales all the time (Generally over weekends) so keep an eye and an ear out for any holidays that coincide with a weekend, and visit their site. (I got the Numark X6 for 76% off because I waited till President's Day Weekend)