Well, Sim, I'll take your question at face value.
First, an ultrasonic machine is not a glorified vacuum cleaner. Not remotely.
Second, sonic difference. I used to clean with a two wand method on a VPI. Now I clean at 80KHz and hear as big a difference as doubling the cost of a component. Many of us have a $3,000 phono stage, or amp, or table, or speakers. Hence cleaning for $3,000 is perfectly viable on a strict cost/benefit analysis, on this measure alone.
Then there is the cost of a factory retip, about $3000 for mine. Since a recent study showed that the grunge in a record groove is one third diamond grit plus grease, which is a premium grinding compound, removing all of that grit should multiply the lifespan of a stylus. $3000 for record cleaning is a bargain on this measure alone.
Then there are the records. If you have 3000 records, it's only a dollar apiece. Even if you buy at garage sales, a dollar each is not significant, on this measure alone.
So there you have it. Out of reason? Not by my analysis.