Once you factor in MIRs those builds end up in the $550 range. I personally lean more towards the Intel build than the AMD one.

That 430W PSU is fine for both builds, but I would go up to the 500W so you don't have to upgrade the PSU if you get a newer card that needs 2 PCI-E power connectors.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i3-4330 3.5GHz Dual-Core Processor ($124.99 @ Newegg)
Motherboard: MSI H81M-P33 Micro ATX LGA1150 Motherboard ($44.99 @ Newegg)
Memory: A-Data XPG Gaming Series 8GB (2 x 4GB) DDR3-1600 Memory ($62.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.99 @ Amazon)
Video Card: Zotac GeForce GTX 660 2GB Video Card ($170.98 @ Newegg)
Case: Cougar Spike MicroATX Mini Tower Case ($34.99 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($44.99 @ Amazon)
Total: $543.92
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-30 18:11 EST-0500)

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($109.99 @ Amazon)
Motherboard: Gigabyte GA-78LMT-USB3 Micro ATX AM3+ Motherboard ($64.99 @ Amazon)
Memory: A-Data XPG Gaming Series 8GB (2 x 4GB) DDR3-1600 Memory ($62.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.99 @ Amazon)
Video Card: Zotac GeForce GTX 660 2GB Video Card ($170.98 @ Newegg)
Case: Cougar Spike MicroATX Mini Tower Case ($34.99 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($44.99 @ Amazon)
Total: $548.92
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-30 18:18 EST-0500)