£ 750 for new spark plugs...

[television]

True, but I guess there is £120 worth of oil, £120 worth of plugs (Swedish prices with tax) and then 4 hours worth of labour, £130 an hour at MB Norwich before discount.
So all in all definitely better and probably not too far off Merc UK dealer prices now.

But, as you say, do it yourself for £250 and a few hours of your time.

Some 10 years ago the labour rate in Stockholm was £150 per hour plus tax for Fords.

Wages in Sweden are much higher than in the UK

 

[Frontstep]

They would not stamp my book if I fitted the plugs, no matter where I bought them

Some consistency would be good in these matters !

 

[television]

Some consistency would be good in these matters !

I agree 100% on this as it makes life very hard as things stand on giving any advice