How can I show prices on most intems, force login on others?

Here's my issue-

Some of the products I sell have protected territories that I cannot sell to beacuse it would be competeing with brick and mortar stores.

I can list prices nationally, but they have to at a 60% margin, instead of the 42% they would actually sell for.

So I'm thinking I could:

1. Force customers to login to see prices on just those items. But can I make it where customer's login must be approved first? Then I can check that the have no dealer in their area first. If they do, then I can refer them to their local dealer, and if not I can approve their login and allow them to see the low prices.

2. Show the product at 60% margin, but have them call for the actual price.

3. Ask them to enter their zip code to see pricing, and if they are located near a brick and mortar store, have a page inform them that we cannot sell to them, and direct them to the local dealer. If there not in a protected territory let them see the prices. Know anyone who could build that in for me???

4. Just have "call for price", which is the worst idea.

I really don't want to discourage people from buying by making this too complicated.

Thanks so much!

Candice