I am using Joomla 2.5.6 and VirtueMart 2.0.8E
When creating a custom attr using the stockable plugin
I noticed in firebug that every time you make a selection, the number of calls to the server doubles!
This is pretty serious and will problem cause some big performance issues for high traffic websites.
It might not just be unique to the stockble plugin, as looking through the code,
something going wrong in components/com_virtuemart/assets/js/vmprices.js seems to be the problem
Hopefully this has already been fixed.