Can I get a cheaper motherboard?

Hardware Hub Motherboards
1

I'll be using a

XFX HD7870 Double Dissipation (FX-787A-CDFC) videocard and a

Intel® Core™ i5-3470

 

I'm currently planning on getting the ASRock B75M-GL, but can I go cheaper without hurting my performance and reliability?

 

Also is 550w feeding enough or should I stay with 650w?

2

550W will be enough. ASRock is one of the cheapest, doubt you'll find any cheaper one.