I have a Mr. Bezos on line 2 for you, he’d like a word.
This has been discussed to death on the Dope.
The Master speaks (1981) (This wasn’t his best work)
All I got is a $100 (2002)
Legal tender and businesses refusing large bills (2003)
Legal Tender (2004) (which itself cited another bunch of threads on that topic, but the links are broken)
Tow truck company must accept 8800 pennies? (2008)
How can government offices refuse cash? (2006)
That last one cites a Web page from the U.S. Treasury, which is no longer accessible as of 2022 :
(…)
This statute means that all United States money as identified above are a valid and legal offer of payment for debts when tendered to a creditor. There is, however, no Federal statute mandating that a private business, a person or an organization must accept currency or coins as for payment for goods and/or services. Private businesses are free to develop their own policies on whether or not to accept cash unless there is a State law which says otherwise. For example, a bus line may prohibit payment of fares in pennies or dollar bills. In addition, movie theaters, convenience stores and gas stations may refuse to accept large denomination currency (usually notes above $20) as a matter of policy.
Note : IANAL, or, to put it another way,
I am not Legal, and rarely Tender in Public, though often in Private.