@dontdisturbmenow have you had to call in tradespeople recently?
We had an electrician come to see why our boiler had gone off, changed a fuse (there were 2 fuses, I'd checked one, didn't realise there was another, I'm not a complete idiot!)... £90
Plumber identified the leak as coming from the shower hose inside the bath where we couldn't see it, changed hose... £80
These are skilled people who do jobs I don't know how to. And they don't have half the overheads of a vet.
As everyone has said, you're not paying for 10 minutes of their time. You're paying for knowledge, their insurance, the building, support staff, etc, etc