Just like the title how much should i pay for a used Evo 9 front bumper with no grills?

 

IMO: Because of rarity of Evo 9 bumper sold used on your local forums and craigslist.
Mint Condition w/ se lip or factory-Evo 9 in near mint quality: $400-500
Normal Condition- dings, scuffs and fade: $350-390
Horrible condition- large dents/guages, missing or damaged bolt/rivet holders, missing fastners, no lip, etc.- $290-340.

-Of course there is wiggle room for negotiating.

I usually see Evo 8 bumper in my southeast region being sold for 100-180 on average. You will never see a Evo 9 bumper under $250.