Bill,
I'm afraid life isn't simple, but this is, if you do it right.
First things first: Purchase your 2nd domain. Make sure that you purchase it from a registrar that includes free forwarding (even some of the more expensive registrars charge an extra fee, so check first).
Each registrar has a slightly different control panel, but what you'll want to do is forward your second domain to your site (
www.iabsi.com).
There are 2 types of forwarding, URL Redirect and URL Frame. If you want the browser to change to "www.iabsi.com" when they put in the other domain, then use URL Redirect. If you want the browser to still display the other domain name, then use URL Frame.
As for as cost, you will have 3 charges:
The annual cost of iabsi.com
The annual cost of your second domain (no charge for forwarding if you picked the right registrar)
The cost of hosting iabsi.com
See? It really is simple.
John