Hi and welcome.
You do appear to have indentified it correctly, but I have some comments which I hope you will find useful.
As Monart, it has what is called the "button" over the pontil scar. A small blob of glass applied after making, and which often supported a label.
I don't think they had labels which were small enough for putting on things this small size, don't worry about the lack of signature or maker's mark - there wouldn't have been one.
The pontil is the blob of glass put on the end of the pontil rod to hold the glass object to it, so the maker can carry on working the vessel and the rim.
The pontil mark or scar is the name for the mark left when this is broken off at the end.
We do not tend to discuss values - they're too subjective, and get in the way of discussing glass which is why we're here.
But do a search on past sold auctions to get a ball-park figure if you want.