I'm NOT an expert but I love art glass and have collected a lot of it.
This base was sometimes called a 6 point star base.
Unless the color is really distorted in the image I think this is Amber and it looks like it could be Viking. Viking had that thick look and feel as well as this kind of style in the 70's (with it's iconic mod pieces being late 50's and 60's)
This could be Murano but there is something about it...that just isn't screaming Murano to me.
Regarding value I can only say this. I have sold many of the more "famous" 60's Viking ashtrays (i.e. the orb ashtrays) for around $40-$50 (depending on the color). So that might give you a very rough idea.
But...do some searching for Viking amber ashtrays and see if it feels like you get closer to your piece here.
Good luck and have fun! Art glass is the BEST