In those price ranges, most likely that AMD will give more for the money.
Im guessing that you have an old Intel dual core (core2duo) and considering a newer rig.
* If you want to buy a new motherboard for the current CPU please write what type of dual core do you have (like e4500 or e6300 etc').
* If you want a suggestion for a new AMD rig, please tell us your budget and what parts you want replaced besides CPU, motherboard and ram.
Enjoy