we have no way of knowing since we have no factual information. such as each of your incomes, deductions number of dependents or other info that could affect your taxes. a joint return is usually the cheapest but there could be reasons - tax and non-tax - why you want to file separately. the only way to decide on what you want to do is see the results by preparing 3 returns - married filing separately for each of you and a joint return.
note that the online account can only accommodate one return. doing a second will permanently delete the first and the third will permanently delete the second. desktop can accommodate multiple returns as long as each is saved with a different name.
