one-off fee for a static IP some time ago and would be a real pain to lose it, especially when most providers these days seem to charge a monthly fee for a static IP rather than a one off cost (presumably because of the shift to CG-NAT)

I got moved to CG-NAT and complained that my phone backup to my home server stopped working - "oh sorry, how can we fix that for you?"

Free static thanks - and it worked