Instead of Amazon, I recommend eBay. I have gotten really good deals there including a socket 1155 (2nd/3rd gen i3/i5/i7 compatible motherboard) for $50. I did not find one quite as good a deal but I did find this one -
New OEM HP Indio-UL8E Socket LGA1156 Intel i5/i7 Desktop Motherboard for only $65 and free shipping! If you liked the performance of the CPU you have, I would get a replacement motherboard like this one.
If you want to upgrade the CPU though, then you might look into a newer gen cpu. Between the motherboard and CPU it cost me about $240 for an i5-3470 and motherboard.