sell or core my ECU?

[4Las90]

I have a 90 FWD turbo Eprom ECU that burned out yesterday. I bought a refurbished one off ebay and if i send the core back they'll give me $100. I have a couple questions:

1. How much could I get for this?
2. Can I take the Eprom chip out?
3. Should I just send it as the core?

thanks for the help

-Bill