What would be a healthy marketing budget?

[Omid A.]

As I am nearing pulling the trigger on my first direct mail marketing campaign, I am spending the rest of this week absorbing as much knowledge from blogs/forum threads on the subject before I build my list and send out the first batch. My goal right now is to just land that first deal as soon as possible.

I know this is a hard question to answer because there are so many factors that affect a person's ability to close (such as negotiation skills) but, generally speaking, what monthly dollar amount would you say makes a healthy marketing budget with the goal of at least 1 wholesale deal per month?