If you want a chance to become a British Citizen, then it may worth the price!
Once you become a British Citizen by either naturalisation or registration (a cheaper method - for BN(O) passport holders only) in the UK, you can automatically pass on your British Citizenship to your children born outside of the UK.
If you have the opportunity to get an UK Tier 2 work visa and you want to move to the UK, I would suggest you to apply for your Tier 2 visa using your BN(O) passport. This will give you the following advantages in the UK -
1) BN(O) holders do not need to register with the local police in the UK while HKSAR passport holders do. This will save you £34.
2) BN(O) passport holders can register to vote in all UK elections, while holders of HKSAR passport are not allow to vote in any UK elections. Being on the electoral roll helps you to build up your own credit history in the UK.
3) You can get British Citizenship via registration using form B(OTA), which is cheaper than naturalisation. In 2017, the cost of registration is £1163 while the cost of naturalisation is £1282.