You've got to careful when ordering these and make sure everything you need is included.
This one comes with the LED strip, controller, infrared receiver, but no plug or power adapter
to power the unit (LEDs run on DC, you need the AC adapter to be able to plug it into your wall outlet:
The other one you link to doesn't specify the number of LEDs per meter or total number of LEDs (or if they do I couldn't find it). These LED strips typically come with either 150 or 300 LEDs (30 or 60 LEDs per meter). The more LEDs, obviously, the more expensive it is. I paid about $80 for a 5 meter, 300 LED strip with controller/reciever/power supply about a year ago, but they've come down in price a little since then. The second vender here also only have 97% approval rating - there are lots of similar vendors with better ratings. You want something like this, check out the description, everything should be included:
New 12V 5M 5050 RGB 300 SMD LED Light Strip + 24Key IR Remote + Power Supply | eBay