You can buy an LCD for the rear of the gopro, but it is not the ideal platform for handholding and playback etc.
If you up the ante to around $500 there are quite a few options.
Do you want or need HD? If not, something like this would work for $322 for a kit with flash card and camera bag etc:
http://www.adorama.com/CAFS400RDKA.htmlIf you need HD, which I would consider a MUST in this day and age, you have to spend a bit more... But for around $500 there are several good options:
http://www.adorama.com/CAHFM300KA.htmlhttp://www.adorama.com/PCHDCSD90KA.htmlhttp://www.adorama.com/SOHDRXR150.htmlOne from each company... There are lots of models and you just have to read reviews and determine what is important to you.
Although if you are going to spend $500 you are treading into the realm of DSLR's that shoot HD video, which would be more versatile and allow you to shoot still pictures as well. Tough call...
I do all my camera shopping through Adorama. Cheaper than BH and the service has been great... FWIW