Ive never found anyone wanting to do it less than £20 in the last couple years
10 years ago you could get them swapped out for a £5, then went to £10, then online sales of tyres only went through the roof, and cant find anywhere less than £20 nowadays. Majors like Kwikfit, ATS, Halfords usually all want £25
Spose they supply a valve, balance it and dispose of the old tyre (Which is now a £4 ish surcharge nowadays)
Thats why ive looked into tyre removal tool at home, which is easy to get, and fix to concrete
Its the balancing thats the pain.
Can get used 2nd hand machines- but dont want to turn my home into a working garage (Want a lift too, but Mrs wont have it)
Already got 3 spare sets wheels in the shed, lol.
For some track days, and most tracks seems to chew my nearside front up in one track day, i go get a used (15") supplied, fitted, new valve, for £25, and the tread is usually pretty good, sometimes even newish. I only seem to loose a second or so when lapping, on rubbish tyres, and I am not looking to set any records, just have fun.