Nice! Here is the idea:
In VM, define a custom field, type 'image' with 'cart attribute' checked and 'is a list' checked (see below regarding the latter).
When creating a product, add as many custom fields images as necessary with the correct price supplement
--> in product detail view, the different option images will display (and be clickable) in a row or column with the associated cost shown below. This is particularly useful when one has to choose between colors for instance.
As for VMVendor, I suppose a dropdown list of the different default images available might do the trick for the vendor to choose from and add the price supplement; the possiblity to repeat this operation (+/- buttons) would be necessary.
Now as a remark, I have to say that I am still struggling in VM to specify default images for a list dropdown custom field image (I have posted in that regard on VM forum). At the moment, when associating a custom field image to a product, one has to choose between all images available in VM ('is a list' unchecked), which is of course not ok.
Hopes this clarifies the matter a bit.
Thanks.