Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
This is a very old system, realistically its current value is negligible. It is far past its service life (many times over at this point) and has really no residual value, and would not be expected to still be functional at this point given the age.
Systems like this are no longer made, tape players are impossible to find, and even cd systems are difficult to come by anymore.
For replacement value however, to buy a new system that would be most comparable in type (a shelf stereo system with integrated receiver/amplifier, tuner, and cd player) with speakers, you'd be in the $200 range.
Here is a replacement I would recommend: http://amzn.to/2afK3DQ
Repairs would not be feasible, there are no parts available for these systems, and the cost of labor alone would exceed the replacement value of the system.