Can I pay someone to hack a LinkedIn Account?
Yes, you can pay someone to hack a LinkedIn account for you, but this does not mean that it is legal. All of the accounts on LinkedIn are property of LinkedIn, so you should ask LinkedIn permission to perform attacks on the targeted account. Agreements have to be signed, and the attacker will have to operate in the window which is provided by LinkedIn.
It is illegal
I do not care how badly you want the account, hacking into accounts is illegal unless clear agreements have been made between the account owners and the attacker. If for any legal reasons, you need to have access to the LinkedIn account, it is advised to contact the official LinkedIn support.