"extra fields" showing in list view

[whoazone]

I've read a lot about various types of extra field issues, but none that directly answer my needs.

I need to be able to place an extra field into the list view and be able to order it the same way your default price does.

For instance, I have horse-related site with 4 main categories, two that need prices requird, and two which price does not apply. In my two categories with prices, the field is called different things - one is a price for a sale horse, one is a stud fee for breeding services.

I can build my custom extra fields denoting these differences, and assign them pefectly, but then on the list view, I need them to show up! I need th prcestd fee to be sorted by from least to greatest .

How can I make the price/fee show up on the main listing view for users and have the ads be sorted by these extra fields? (like cheapest to most expensive)

(and if I can accomplish this, I will be able to disable the defualt price field so my non-priced category cutomers won't trip over that field when they list their non-priced ads! Its kind of a pain trying to serve everyone's needs)

Thanks.