It is super-easy to do yourself.
Waxing – £5 cheap clothes iron (preferably a non-steam one as the wax can clog the steam holes), wax around £2 a block from ebay, length of straight perspex to use as a scraper (couple of quid).
Edge tuning / detuning – edge tool £10 delivered from ebay. File and diamond file blocks a couple of quid from any DIY shop.
Base repair – for an extruded base its hardly worth fixing minor dinks as the board will generally run ok. For decent sintered bases you can buy some UV cure Solarez repair for around a tenner on ebay. Serious dents / core shots usually require a PTEX stick.
The only thing I’ve ever needed doing at a shop was a stone-grind on the base of a pair of sintered skis.