> after which the contract and employment ends

Is is a contract (you are self-employed, pay income tax etc) or is it employment (company employee, they withhold income tax, standard W2 form)?

Contracts pay more, lot at least they should, because the contractor has a higher risk, less benefits (e.g. no holiday entitlement), more cost (taxes, insurances) and liabilities (as a contractor you need to have insurance in case you screw up while working).