Hello -
I can offer a viable workaround for many custom field frustrations, as long as you don't need parent/child products. We created a new extension was built for a much larger purpose, but it can also easily solve many custom field challenges like the inability to sort options in a dropdown list however you like.
A client recently came to us a few months ago with a challenge: Enable VM2 to handle interdependent custom fields, including database lookups outside of VM2, with conditional fields and cross-field validation. This client needed to sell a bespoke tailored product that requires almost 40 (yes forty!) custom option choices.
As you can imagine - this type of complex custom field setup simply can't be done in standard VM2 without some serious hacking. And to the best of my knowledge, you can't really do it in any other Joomla eCommerce extension either.
So being the stubborn Geeks that we are,

we finally found a way to make it happen - with NO hack!
We created an extension to seamlessly integrate a completely custom Crosstec Breezing Form into the custom field area of a VirtueMart 2 product. Because BreezingForms is a fully featured form development component, this means that you can do all those great things you expect from best selling form design software, then use that form as the way to capture product options and attributes for a VM2 product.
And of course, because you are using a form design component, you can control the ordering of dropdown options and other product selection fields almost any way you want.
If you think this sounds like it might help you, here's a link to our documentation to learn more:
http://docs.polishedgeek.com/wiki/display/BFCUSTOM . There's a also a YouTube video there that explains it a bit more.
You also can learn about what you can do with the form component by Crosstec here: Crosstec BreezingForms
http://crosstec.de/en/extensions/joomla-forms-download.html P.S.
Please note that while this integration CAN adjust product prices, it only tracks stock at a product level. It does NOT track stock by each individual form option answer. So it's not an alternative to parent/child products if you need to track stock in detail by options/attributes. From reviewing the thread here, it sounds like it could help several people with their VM2 custom field problems.
P.P.S. - I hope this post is acceptable here in this forum because it offers a specific solution to VM2 challenges posted. If this is not acceptable, I will be happy to remove the post. Just let me know. Thanks!