Basically, you are paying him a premium because he doesn’t want or need a half day job.
Half day jobs are inconvenient bevause, depending on where you are, they can wipe out the whole day in travel time, and also many people now do their own small DIY jobs so filling the other half-day is more difficult.
On the one hand, I wonder at all the young people off to do expensive, vanity courses at uni (I was one! I hold my hands up) when trades are basically a licence to print money if you work hard and are honest, law abiding and treat customers well.
On the other, I feel a market correction is coming whereby a lot of people will no longer be willing to pay megabucks to shady geezers for essentially labouring jobs they can do themselves. When I was growing up in the 80s and 90s in the north, the idea you’d routinely pay someone to fix a sink leak/ paint or paper a wall/ repair a fence/ put up some pictures/ assemble a wardrobe/ change some spark plugs, was for the birds. You did it yourself and the world kept turning.
Obviously I am not talking about safety-critical and insured/certificated trades like gas fitting, electrics, structural building works etc.