May I ask which firm gave you a quote of £200-300 to replace the heating element?
Sorry for the delay in responding.
Appears I must have misread, I can confirm the fault code would suggest a faulty heating element.
A replacement element would be around £60 from a spares firm such as the one here, and your looking at about an hours labour to replace it which depending on your locality would be between £40-60.
If you would like me to recommend a engineer to replace this part, please provide your postcode.