The maximum limit for cash payments in Italy is 1000€, so 3k would still be a lot. Why would someone need to pay for 10k in cash? Where does that cash come from? 60% of the times, it's money laundering every time. edit: I suppose since I'm in EU and I'm only 30 I'm "used" to the 1k limit, while non-EU (or specifically USA) people might be grabbing their pitchforks.
Whenever I buy a car, tractor, cattle, pump repair, implements, out-buildings, solar system installation, fuel storage, etc... Because I pay cash and keep the bankers out of the transaction it costs me less and it costs the seller less. I negotiate this ahead of time. Most people in business would rather have cash in hand than wait on the bank and pay their fees.
Other way around (in the Netherlands, which is the subject), bank transfers are free but depositing cash as a business costs money. Paying cash costs the seller more and holding it has a risk of robbery.