you don't get dents in urethane bumpers.

if the "dent" was always there since you bought the car than it could be non oem bumper replaced if the car was in an accident. and the "dent" is probably just because it's not oem and lines don't match up perfectly.

if it happened after that.

perhaps some how it got pushed, and something is pulling it in.

but urethane doesn't dent.

new oem bumper can be had for $100-$150 depending on your hook up. and then the price of the rs lip and paint.

so it's up to you.