It's not THAT bad is it?
Oil, coolant, brake fluid, about £80 in consumables to do it DIY anyway, then wipers, £30 isn't a crazy amount.
So £110. £250 for labour, and coolant, oil and brake fluid will be a good 2 hours I'd say, bleeding each calliper through, wheel off each corner, then back on, coolant, bring system to thermostat open, check for airlocks, bleed through.
I bet an independent would charge £250, and it's not a BMW dealer stamp, so maybe £100 impact on value/ease of sale come resale time.
Try own something French and use their dealers, THEN you will know pain when it WILL go wrong (often by their doing from last time they touched it

)
Dave