If you want to make it cheap and legal in a R44, then become a member of a R44 share, there are a few across the UK.
Compared to self fly hire prices, the R44 share is a cheaper option.
And to make it a bit more cheaper, you can let your friends pay for their part of the fuel (not 100% sure if you can let them pay for their part of the total cost).
Don't know how many hours you need, but if it's from basic PPL to CPL, then it's cheaper to get a R22 rating and go to the USA for a month and build your hours there.
Then come back to the UK with still 10h left and fly your friends around in the R44.
Lots of options but I wouldn't fly on the edge of the CAA rules
