Used Torah

I've never really gotten into the second hand sefer Torah business, however recently a shul here bought a few new sifrei torah and couldn't finish paying for them. As a settlement, Rabbi Yurslavsky paskened that they could give me some of the older seforim and I could sell them and take the funds off what they owe.

I'm not looking to get top dollar and this may be a good opportunity for someone looking to buy a second hand sefer. I plan on advertising them.

However I have no idea what to charge.

 This is the best one (pictured). Its alter rebbes ksav, (new it would be $35,000 -  $40,000), second hand I'm sure is a lot less. Its in very good condition, NOT a pre war holocaust sefer, the entire sefer is jet black ink with black tagin‎. Clear beautiful writing, see attached picture. Even the sirtut is strong.

It's also smallish and light (I think 45cm klaf size) so its not like the older heavier ones.

Any Ideas how to price something like this?

Advice would be appreciated....