The bumper does split into two so you can get just the lower half. 2nd hand these can range from £150 to £250 (for genuine). From the dealer its alot more.
Then the exhaust sorround you can get one with cut outs for the standard exhaust, quad or R32. If going R32 you will get them trim with the bumper usually if your going different thats anything from 169euro to $400+ for Carbon Fibre from Osir.
If your changing your exhaust you will be looking at £300+ (2nd hand) up to £1000+ (new) depending on style, CBE, TBE etc.
ANd you have to get it painted so around another £100.
I'm doing this atm and so far a bumper, CBE Quad exhaust, centre trim (all 2nd hand) has cost me £600 without painting.
Hope this helps