Be specific in spelling out your needs. A written inquiry will show that you're a serious customer who wants to make an informed decision.
1234, Main Street
Boston, MA 02123
<Recipient Address Goes Here>
Our company is interested in the cost of leasing <type of equipment> from your company. Our office has <number> employees and the machine will receive <heavy, moderate or light> use.
Beyond that, we're looking for the most economical solution, with high quality and excellent service. Please send me any information you might have and if it looks like you can satisfy our needs, we'll be happy to meet with one of your representatives.