For anybody in the OKC area, the Edmond Academy store has 12" thermometers on sale for $3.99, regularly $14.99. I thought it was a mistake at first, as they weren't marked as being on sale on the shelf, but it rang up correctly as a 12" thermo.
May or may not apply to all Academy stores.
With the credit we already had at Academy, I was able to pick up a hinged 22.5" Weber grate and a 12" thermo for a total of $3.8X, making my total UDS investment so far only $35 ($30 used unlined drum + today's purchase). Still need hardware (including nipples (tee-hee)), a charcoal grate, and expanded metal, though. Not a totally fair estimate considering we, at one time, gave money to Academy in order to have a credit there, but don't harsh my buzz, man.