QUOTE (Jack_mcs @ Jan 17 2007, 11:45 PM)

Paypal standard is the only choice for low-cost options (don't even think about 2CheckOut, in my opinion). It only charges a per item fee. All of the rest of them (at leas tthe common ones) charge a month fee starting at $20 plus fees. Authorize.net probably won't allow you to have an account unless your monthly gross sales is at least $1,000. Without such gross sales, it doesn't make sense to pay a monthly fee.
Jack
I am pretty sure that is not true, that auth.net won't let you have an account at < $1k / month.
Most merchant account providers actually like having low-volume customers because it they charge a minimum fee of $10-20 / month and they also get a commission off of the minimum (although you can negotiate lower through your merchant account provider, but not if you call auth.net directly) $20 gateway fee from authorize.net. There are very little costs associated with servicing such an account (since there is no volume) so they make a decent amount of money off it.
Remember, the merchant account is one thing, the gateway is another. They are seperate.
I agree with your main point, though, if you are just testing the waters Paypal is the best option. We spent about 2 months using paypal and then switched to a merchant account + auth.net setup because paypal was confusing some customers.