The variability of renewable energy resources, such as wind, imposes a challenge to power systems operation. Energy Storage Systems (ESSs) can be employed to compensate this variability. However, due to the elevated costs associated with ESS installations, there are concerns about their economical feasibility. The trading of energy within electricity markets, known as arbitrage, has been proposed as a method to ensure economical feasibility. ESSs are known to suffer from degradation during its usage. From an economic perspective, this degradation process can be considered as a cost of use. This paper is focused on analysing how this cost of use should be taken into account in order to improve arbitrage service revenues. A literature review on trends of cost of use estimation is performed. The cost of use related with battery ageing caused by cycling is studied by means of an ESS model with capacity degradation and variable efficiency. The costs of use based on variable replacement costs or on expected future opportunity costs are proposed as the main contribution of this work. This method is demonstrated to improve long-term revenues compared with existing solutions. The influence of such models into BESS operation and long-term profitability is addressed using a case study where an ESS performs arbitrage in the Spanish Day-Ahead Market during one year. Results show how a more restrictive cost of use improves profits per circulated energy ratio, optimizing the device's usage.