Although its not such an expensive phone I heard its a little slow and also u can't see what time someone text you or called.
Then splurge for the Droid Pro. It's still within your price range, even new ($180 on ebay). If you want to save some money, try DrDanny's suggestion.
You don't have unlimited choices, there is a limited set of phones that can be activated on
PagePlus, and you've narrowed it down to a very small group with QWERTY and WiFi. I only listed candybar phones, if you're interested in side-sliders the list expands somewhat.