How much does it cost to set up a merchant account for e-commerce?

Use PayPal. They are friendly, helpful, and free to sign up. You just need a bank account which you can use as a base for the account.

With PayPal, you can accept credit cards, bank transfers, paypal payments, and have other features available.

The only cost is when you sell something. Then you only pay a percent of what you sell in fees.