Is it worth the promotion?

I work in sales and earn around £50,000pa at 27. My salary however is only £25,995pa, but due to the amount of services I sell I make on average £24,000pa in commission. I’m good at the job, very reliable and have never had a day off sick in 9 years so the Operations Director has asked me if at the beginning of next year I will be willing to move up to head of sales, managing the sales team.

However, and here’s the catch, my salary will increase to roughly £35,000pa, but I won’t sell anything due to being a full time manager with more responsibilities managing the team.

I’m struggling to get my head around taking on this promotion with more responsibility, but earning £15,000pa less? I’ve just bought a house and need every penny I can get!

The ops director said if I take the job I will be in a good position to move up to director level in the future and taking a pay cut for more responsibility is normal?

Just want to get everyone else’s take on my situation.