Paid $875 including 1917 bayonet w/scabbard for mine (pic in your other thread as of this morning). $750 of that was for the gun, $125 for the bayonet. I haven't seen one in better shape or for less money (certainly not both) since then, so no regrets. In fact, judging by the upsurge in interest in recent years, I may have just got in under the wire.
My opinion is that these guns (1897's in general, but trench models in particular) will appreciate significantly in coming years. I base that opinion on the fact that there are not many 100+ year old models that offer both provenance and safe, reliable shooting with modern nitro loads. Collecting is great, but most of us want to shoot what we collect. The rich history of the 1897 is just a bonus.