How to do a "if product is priced by attributes" query?

Some of the products in my shop are provided in smaller samples.
These are priced by attributes and i would like to make it clear on the product listing page which items are available in sample sizes.

I imagine there's a way of looking up which product ids are priced by attributes - can anyone help out?

If i could query whether a particular option value is being used even better!

In the products table the field products_priced_by_attribute is either 0 or 1 ... 1 being that the product is Priced by Attributes ...

Ah, ok - so i could use that, is there a similar field to say which option value is being used - this way any other products i choose to price by attributes (but do not offer sample sizes) will not show up

Any pointers on the code?

added

p.products_priced_by_attribute

to queries in default_filter.php