For a 500 looking back at mine
50 hour £ 650
100 hour £ 1200
annual £ 7500
All the above is assuming no component changes and normal ags plus some normal wear and tear parts ( based on 300 hours on a 30 year old machine)
Worst ever annual was £ 18k but that included turbine change and fitting of a filter barrier system plus £ 4000 of rectification work