Bavarian Crystal WW1 - can someone confirm authenticity/value?

I received 3 pictures of items I am considering purchasing; the 1st is of a wine decanter with 4 glasses; the 2nd is of 17 matching glasses; the 3rd is what I am told is called Lusters; the pictures are attached. In my conversation with the seller, he says his grandmother died and he has been left the pieces, that they have been handed down in the family, that they are Bavarian crystal from WW1 and that they are true antiques. I did ask about any “stampings, stickers, engravings, or etc.” that would show the pieces were as stated, his answer to that is as follows:

“I spoke to someone who was involved in Antiques with the twin brothers on Antique Roadshow (can’t remember their names) and asked if I should be looking for markings and they said no.  Their indication to me is that the fact they have no markings dates them to prewar.  I will check but I haven’t seen any.  Anyway that is what they told me after I sent the pictures to them (LEIGH KENO!!!  I REMEMBERED!!).  Don’t know if that helps or makes sense but it is what it is, so to speak.”

If you have a minute to look at the pictures and give me your opinion as to the probability of the pieces being crystal (as opposed to cut glass), Bavarian crystal, WW1 Bavarian crystal, or of any value at all, etc. . . . I would be greatly appreciative. Assuming the best in people, and that these pieces are real Bavarian crystal pieces in good condition; do you have a recommendation as to the maximum I should pay for the decanter with glasses, or the 17 separate glasses?

Thank you for your time, it is much appreciated.   [email protected]