STORY: :: eBayGameStop wants to buy eBay. The retailer said Sunday that it has offered to buy all common shares of the online marketplace for about $56 billion.Chief Executive Ryan Cohen said the offer price is $125 a share in a 50-50 mix of cash and stock.The bid represents a premium of about 20% based on eBay's Friday close.In an interview with the Wall Street Journal, Cohen said that the move would create huge opportunities to improve earnings and cut costs.:: eBayHe added that the combination "could be a legit competitor to Amazon."If eBay is not receptive, Cohen said he was prepared to run a proxy fight and take the offer directly to shareholders.He added that he has secured a commitment letter from TD Bank for about $20 billion in debt financing.:: eBayNeither the lender nor eBay would immediately respond to Reuters requests for a comment.The proposal comes as GameStop grapples with disruptions from a shift toward online shopping and digital purchasesAccording to Reuters calculations, the company has a market value of almost $12 billion, compared to $46 billion for eBay. That means the potential deal would upend the usual merger and acquisition playbook, as it's rare for a public company to target one nearly four times its size.