They are worth as much as someone is willing to pay for them.
Take a look around at some auction sites like gunbroker and so on. You may be able to get an idea there.
__________________ If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen. ― Samuel Adams