My private dentist in Slough charges £85-95 for a filling and £450 for a porcaline crown. Root canals are about £350 on top but are not always necessary for a crown.

Expect to be charged for an x-Ray, course of antibiotics and maybe a replacement filling. You could probably reduce the price with a temporary filling and skipping the antibiotics. Wouldn't recommend the later if you are in pain though, tooth ache has to be one of the worst type of pain and I have two rounds of major abdominal surgery to compare it with