I only spent about $500 on the first big-block dry sump setup that I built. I used a wet sump pan with a swinging pickup and just hooked that up to the dry sump. I rounded up a used pump from a circle track team that was upgrading and found a cheap tank from someeone else who was upgrading. I built my own lines and used the cheaper brass and steel fittings rather than the expense aluminum ones. That dry sump setup worked just fine. The pump wasn't big enough to pull much pan vacuum, but the system had good oil pressure and I had all of the benefits of a dry sump. I covered the topic a little bit in this article:
http://www.hotrod.com/how-to/engine/mopp-1206-project-505-the-final-chapter/