Nakamichi CA-5 Flea market find

I'm a old retired expat living in northern mexico and a flea market addict. Most of the sellers bring stuff from Phoenix and Tucson to sell. I've found many interesting items because they really don't know what they are for or the true value.
One day about a year ago, I came across a NAKAMICHI CA-5 PREAMP.  
I bought it for $10. 
I am not an audiophile by any stretch of the imagination but I do have a good memory (still) and remember the name NAKAMICHI as being what I thought was a high end product from when I was younger. 
Well anyways, I brought it home and hooked it up to the headphone jack on my laptop and hooked some speakers to the output and there was hardly any volume. LOL 
I figured that was a waste of $10. Then my brother told me what a preamp was for. 
So I hooked it up again to the laptop and hooked the output to the input of my regular amp and WOW!! The volume seemed to double and sound so clean. I was amazed.
Now I know what a preamp is used for. 
My wife runs a ZUMBA class and I was using the CA-5 with a cheap amp with 4 speakers and the sound was pretty incredible.  The other day the cheap amp quit working and I bought an ONKYO TX-8211 at the flea for $40. I hooked that up directly to the laptop and it sounds pretty phenomenal to my ears so I don't need the CA-5 anymore.  I think the ONKYO must have some kind of built in preamp. 
I was thinking about putting the CA-5 up for sale on the AUDIOGON PAGE but I don't want to bother if there is no market for it.  It works perfectly but it has some chipped paint on the top or the case. I imagine from the flea market guys transporting it. Otherwise it looks decent. It has all the original knobs and the plastic thing on the phono input.
Should I list it for sale or is it a waste of time and a $10 fee?