Hand it to eBay CEO Meg Whitman: She knows a bargain when she sees it. The online auction giant said Monday it would buy PayPal for about $1.5 billion. That’s a fair enough price by any reckoning for the Internet’s most popular electronic payment service. But when the teeming masses of eBay bidders and sellers get thrown into the mix, PayPal truly becomes a bargain. Indeed, with the right marketing it could one day join the likes of Visa and MasterCard among the heavy hitters of consumer payments. It was just as smart for PayPal’s board to see recognize which way the wind’s blowing. As Reuters notes, the company already derives about 60 percent of its business from eBay.