Help with value vintage Line Transformer Altec 2282

[ckrocks77]

Hey guys - my step-dad is asking me to help him sell his vintage electronics stuff & I'm having trouble finding value for this Adjustable Line Transformer - I know all about the 15095's but these 2282's are difficult to find.
Any help would be appreciated - as in, what would a working pair, or individually, be worth.
Thanks & keep rockin!
Peace love and light from Northern Cali!!