My stepfather gave me a smoker that he built years ago. Initial investment ~$7 for a new water pan.
My brother in-law and I really liked the way it did a hot and fast brisket, so we decided to improve on it and start using it for comps. So we added urethane casters, sealed the bottom, had a heavy duty firebox made, new grates, fitted it to work with a guru, new handle on the lid, counterweight on the lid, holes for probe wires, a guru shelf, and a water "pan" that can be filled from the outside of the smoker. I had a fabricator friend do this, and it somehow ran up to $450
After one contest, it's started to pay for itself already :D
The water "pan" is an old bottle of some sort (oxygen or a fire extinguisher or something). It's only about 5" wide, but it's 3/4 the length of the smoker. It has holes down each side at about 10 and 2 oclock, with a channel to keep drippings from going into the holes. This way, the drippings still get in the fire, and we still get the steamy goodness.
The day after I picked it up, I decided that since the smoker looked ridiculous, it needed a ridiculous paint job, and I've always been a fan of the P40 nose art, so another $60 went into some ceramic paint.
Here it is with the paint almost done
Here it is, dirty, mid cook, and showing off the part I forgot to paint.
So, initial investment $7.
Present investment, around $517.
Bring on the "shoulda built a UDS!".