It really depends on what the individual employer is looking for. There will be outsourcers who are happy to do this for minimum wage. But will you be happy with that?

$15/hr is the minimum I recommend for freelancing sales opportunities. If you're doing outbound calling, more. I've charged $30/hr freelancing through sites. But I have expertise that makes me more valuable than that; they know they're getting an amazing deal. And I won't call for just anybody.

If it was tech support alone, ie. no selling, then the hourly rate might be lower as the calls are inbound and there isn't any selling. Maybe $10 or $12.

Look at the value you're creating for the client. What is a sale worth to them? How many do you think you'll be making a month? Multiply those numbers together. This is the total monthly revenue you bring in. You want at least 10% of that; work back to your hourly rate from it. Now here's the acid test: if the hourly rate is too low for you, you know the opportunity doesn't have enough money in it to be worth your time. Make sense?

Since this opportunity was two months ago, I'm sure it has long passed. However, I wanted to provide an answer for people in the future who have a similar question.