£200 and that's buying some tools which you won't need to buy again.
I started servicing my own about 8 or 9 years ago. Bought a twin max, a brake bleed funnel, a good torque wrench and feeler gauges, more recently a GS911. When I first checked the valve clearances on my 1150 they needed adjustment (previously done by a BMW dealer) they never needed doing again, now it have a 1200 cam head and that's even easier. My guess is about £100 per service (oil is the dearest item, plugs the plugs when due) get my oil from Moto oils and buy enough for 2 or 3 services at once. Always do the shaft and gbox oil every 6000, I know it's not needed but it's so cheap I feel whilst I'm draining the sump I might as well do all the oils at the same time. When I sold the 1150 RT I never made a loss due to my home servicing in fact the purchaser was more happy with the fact that I had done it and kept detailed records. I don't do it all at once, one day when the bike has been ridden and engine warm, when I get home I do the oils. Another day when the engine is cold I do the valve clearances, strip the brakes clean and replace them. Another day I will finish the job, normally over about a week period. My 2011 GSA is due it's 24000 service in 1000 miles time which includes alternator belt, but looking at the Jim Bon vaden video it looks simple.