What you have there is a rare, but not necessarily valuable, piece of Rarotonga, Cook Islands, Glass. You can see Raro and Cook Is, as well as possibly Tim or Kim. I thought I had written this up on my newzealandglass blog, but it seems I mentioned it only in passing:
http://newzealandglass.blogspot.com/2013/06/keith-mahy-one-of-pioneers.html In 1997, Keith Mahy and others (Garry Nash, Shona Firman ...) developed the Beachcomber Glass Studio in Rarotonga, followed in 1999 by a training course there for young potential Rarotongan glass artists.
I have two pieces, one signed by Garry, and one by Apii Rangi - I will write a blog later today.