This was the comment I was looking for. I can't believe a 150 person company needs 4 (or 3.5) developers working on its ERP system. You either have the wrong ERP for the job or incompetent developers.
That's between $250,000 to $500,000/year to support an ERP system. You could outsource the whole think to the most expensive provider and not pay half of that. We do massive ERP automation projects for Fortune 500 companies at a fraction of that cost with even lower on-going maintenance.