Lots of great advice, but the last sentence of your post made me smile.... I'll keep chugging along till I meet the smoker I've been dreaming about.
Finding the right smoker is like cooking a brisket...lots of patience are needed. Before I built mine, I bet I spent a year surfing here, smokerbuilder and numerous other sites looking at pits, not to mention inspecting every pit or smoker at the big box stores getting ideas and deciding exactly the route I wanted to take. I know Craigs list has been mentioned, but around here we have a web based classified ad site that there are always 15-25 pits for sale at anytime, maybe there is something similiar in your area? Just a thought. I agree with others that finding a local welding shop that might build it for labor if you can round up the materials would be a great choice. Check local scrap yards for pipe, plate and other items needed for your build and you will come out way ahead of the game. I think with some effort you could round up the materials for less than $500 for a good 36-48" model and then have it built for less than $500, coming in under your budget. If you need smoker plans, they have plenty on the smokerbuilder site for purchase.
Best of luck and keep us updated.