Buyer agents will charge either a fixed rate or a percentage fee of the purchase price for their expertise.

买方代理或者收取固定的服务费，或者按照购买价格收取一定比例的服务费。

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In general, securities firms and Banks to investors to provide this service will charge a fixed interest rate.

一般来说，证券公司和银行向投资者提供这种服务将收取固定利率。

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So too with so-called PLUS loans, for which Mr. Obama favors the 10-year Treasury rate plus 3.93% on a fixed-rate loan with no cap, while Mr. Kline wants Uncle Sugar to charge a floating 10-year Treasury rate plus 4.5%, while capping rates at 10.5%.

WSJ: Review & Outlook: Obama's Student-Loan Props