No, orders of magnitude are exponential, not linear, so conventionally “on the order of 1 billion” would be between 100 million × sqrt(10) and 1 billion × sqrt(10), but “billionaire” isn't “net worth on the order of 1 billion” but “net worth of 1 billion or more”, or, when used heirarchically alongside trillionaire ans millionaire “net worth of at least one billion and less than one trillion”.
No, orders of magnitude are exponential, not linear, so conventionally “on the order of 1 billion” would be between 100 million × sqrt(10) and 1 billion × sqrt(10), but “billionaire” isn't “net worth on the order of 1 billion” but “net worth of 1 billion or more”, or, when used heirarchically alongside trillionaire ans millionaire “net worth of at least one billion and less than one trillion”.