Side question: In the US is everyone FORCED to accept the USD? I know you can accept other money but do you have to accept USD?
Legal Tender Status
"I thought that United States currency was legal tender for all debts. Some businesses or governmental agencies say that they will only accept checks, money orders or credit cards as payment, and others will only accept currency notes in denominations of $20 or smaller. Isn't this illegal?
The pertinent portion of law that applies to your question is the Coinage Act of 1965, specifically Section 31 U.S.C. 5103, entitled "Legal tender," which states: "United States coins and currency (including Federal reserve notes and circulating notes of Federal reserve banks and national banks) are legal tender for all debts, public charges, taxes, and dues."
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...."http://www.treasury.gov/resource-center/faqs/currency/pages/legal-tender.aspx
Seems like you don't have to.