Forerunner 35 and hr strap?

I have recently started running after some time off. I have the Forerunner 35 which suits my needs for the most part. I want to start utilizing heart rate in my training and I don’t feel that the wrist based heart rate on the 35 is too accurate. Should I get a compatible chest strap or does it make more sense to bite the bullet and invest in a new forerunner?