Are accountants prohibitively expensive in the US? I don't use any tax software myself in the UK - I just pay an accountant $250 once a year and he does it for me (using some software I presume.) It's not really on my radar as things worth trying to automate or use software myself for, let alone building my own software! I'd have to be able to do it in just a few hours to be cost effective.
At that price point, your accountant is just charging you to do the data entry into Turbo Tax or equivalent. It's more work to coordinate, and and provide all the info, and costs more.
People in this thread are talking about literally writing their own software to do it. Half an hour to collect up my payslips and email them to an accountant for $250 can't possibly be more work and cost more?