Hi Sveinborg,
I paid approximately 80 euros for single trip Trek insurance through the BMC. However, BMC insurance requires you to be resident in the UK and despite my best efforts to investigate my residential status with the British government, I couldn’t get a straight answer… it’s quite possible my insurance was invalid 
The Bupa insurance is for an upcoming trip to The Caucasus and I paid around 160 euro premium, again for a single trip. It’s double the price but this reflects in the quality of cover.