Virtual bytes are the post-SegWit size measure: witness data (signatures) counts at a discount, which is why modern address types are cheaper to spend. A typical simple payment is ~140 vB, so at 10 sat/vB it costs ~1,400 sats — whether it moves $10 or $10 million.
The live sat/vB tiers (economy / standard / priority) are on our fees page with the dollar cost computed at the current price, and the mempool is the auction floor where the rate is set, second by second.