Restricting product to certain registered customers

[KrispysKingdom]

I would like to make some of my products only available for certain registered customers to purchase.

For example:

A customer orders custom-designed business cards. I would like the design available in my store for future purcases, but only by the original purchasing customer.

Is it possible to set up a text field for the product that a pre-determined secret code needs to be entered into to be able to add the product to the customer's shopping cart?

[gjh42]

You might investigate the "Call For Price" option. It doesn't allow immediate purchase but requires contact. I don't know how it deals with actually completing a sale, as I've never used it. If you find out anything useful, please share!