There are several varieties of phone headsets that run under fifty dollars. Cordless models allow you to free your hands and body. Like other cordless phones, these have a plug in base and a mobile component. The mobile component includes a headset. Some you can strap onto a belt or pocket.
Radio shack carries modestly priced headset phones.
Most of their cordless phones now have headset jacks. Other brands are Panasonic which makes a good quality cordless radio phone that offers a headset unit. Plantronics carries various phones with headsets. Shop around at discount stores. Make sure to check return policies so that you can check the quality and comfort of the phone at home before committing to it.