This is NOT a Sparrow.

Inasmuch as - they don't go "Cheep".
You are gazing at close to 390 quids-worth of "DPF" = Diesel Particulate Filter.
This, with attendant "EGR" = Exhaust Gas Recycling valve, plus assorted odds and sods and labour, which, incidentally, I can't see listed (Maybe factored in) shoved it up around the 4 figure mark somewhere.
If there is a consolation, it ought to be good for another 9-10 years, since that's the how long it took to manifest itself; which is probably more than can be said for me?
;¬)