What is a 65 barracuda worth

It's all about condition and content . So without at least some pics and an idea how it's equipped it's really difficult to give an accurate estimate on fair market value.
Generally I would start at $3000 for something solid that you can drive home and add or subtract from there.
I like to think in terms of fair market value, what I might be able to sell it for which might be a lot less than what I'm willing to pay.