Well Superted, if you pass everything first time, maybe it would be £31k.
I was under the CAA system, did my PPL and IMC in the UK, Night, Multi and Hours Building in the States, BCPL, CPL/IR upgrade and MCC in the UK, so it is very similar to the modular route.
I did it over three years and it cost over £40k, and I passed everything first time.
Don't forget to add in CAA fees for examiners (approx £500 a test) and issue.