Value of Beeman R10

[optimum7]

I am pondering the idea of selling my Beeman R10 that I have owned since new in 1989 or 1990.
is the standard version, right handed.
Anyways is a .20 cal, stock is a 9 in my opinion, the barrel is a 9.5.
I probably have shot around 1500 rounds since new. no mods whatsoever other than I have a Scope on it.
I do have the Iron sights.
anyways suggestions of value will be appreciated.

[Mark 611]

what condition is it in?

[optimum7]

It is in Very good condition, I say between 8.5 and 9.0 out of 10.

[Mark 611]

PIX would help! but to take a guess $300 to $400

[optimum7]

Here is a pic I just took.
Than you for your help.