I've noticed DVD players have a great variance in cost. Why is that?

I am in the market for a new DVD player. I currently have an older Sony one that I will now be used in my family room. My budget is $300 max and I know there is a huge price difference with DVD player. I would prefer to have a 5 disc player, but it's not a requirement. It would be hooked up to a Yamaha 5760 receiver and a basic 32" Sony TV (non-HD, non-flat screen)- 60% HT and 40% music.

What options should I be looking for?
*Progressive scan?
*SACD?
*Others?

Any players you recommend? Certain brands I should consider or avoid?

Thank you!
Eric