belles 250 amp/ xlm stereo pre

Hi folks...just inheritated this older Belles gear...any idea what this equipment is worth? They both are roughly 20 yrs imagine not much...more curious than anything else...I do have original box and manual for the amp...not the pre..thanks...also...havent installed this in my system yet...any thoughts on how these rate vs. more modern gear?
It may be worth more than you think. I no longer subscribe to the AudioGon blue book, so I do not know. Belles is well respected and it would not shock me if it has held it's value reasonably well over the years.