Well... it was almost a year ago that I posted that, and the job is long done.
But by cheap, I meant single use. Good enough to power a vacuum sander for a single job.
At the time, Home Depot had a GoClean Wet/Dry Vac, normally (allegedly) $99, on sale for $20. Don't know why, because it is not horrible. A little cheapy, but for $20 I could hardly complain. It even has a HEPA filter. It was the ideal solution for the job.
Though I do not see it on HD anymore. I guess it was on clearance.
I found it (out of stock) somewhere else
, and this is what it looks like: