How much does a Premium Only Plan cost? br Typically a section 125 plan document and necessary forms will cost anywhere from $100-$600 through an attorney or tax advisor. Many payroll providers charge set-up fees as much as $600 but once you have the document you will be required to update as new legislation is available. A Premium Only Plan will cost only $89 a year if you choose www.taxfreepremiums.com as your document provider, which includes all mandated updates. br Website: br Phone: 1-855-447-3375 br Email: Austin@taxfreepremiums.