Some prices. It's not like billionaire spending will influence the local carrot prices. They're unlikely to overlap at all with most day-to-day spending for normal people.
But the bigger flaw in your logic is that investment is a good things. We want investment in plants, warehouses, technology, pharma. That is what wealthy people do with their excess money is speculate and invest in these new things that will serve everyday people.
If you give that money away the people who recieve it are not going to invest it. They are going to blow it on trivial things and consumption.