Help Dating & valuing old bikes Huffy & Diamondback

[samfran]

I know nothing about bikes but these vintage reconditioned ones spoke to me. My son never ended up wanting to ride so I want to sell locally. Anyone have insight on what year they might be and value? I mainly sell clothing and random kitsch so literally clueless on these. I can see the orange is a sand streak 6 diamondback bike but can’t make out the black.

 

[J-wagon]

The orange 1980s DB sand streak 6 originally multispeed, looks converted to singlespeed. Front rim maybe Araya but rear not matching.

Black is Huffy.

 

[samfran]

The orange 1980s DB sand streak 6 originally multispeed, looks converted to singlespeed. Front rim maybe Araya but rear not matching.

Black is Huffy.

Thanks so much I was guessing it looked about 80s. What would you estimate I should try selling them for locally?