Hi Shawn,
If screening and gathering information is what you need, then a VA can be a good option for you. Though I am not quite sure how they would be able to scrape info from direct mail campaigns for you unless your VA was local. A good alternative could be to have a VA scrape the internet for leads for you, and put them into an organized form for your review. In addition, you could also put up a website for lead generation and have your VA make fielding phone calls to your leads on your behalf and report the details to you for you to follow up with.
As far as running comps is concerned, it may not be very easy for a VA with no real estate background to run comps for you. You can teach him/her how to do it, but it would only be a good investment of your time if this is something that you REALLY need to outsource and can be done with little to no input from you. You could on the other hand come up with a fill-able worksheet to compile all of the data you will need to run comps on a particular property, and have your VA do all the necessary research. Then, you could run your own comps based on that info.
So, as you can see, using a VA can potentially be a good investment as it concerns your wholesaling business. The biggest question is just how you will utilize them. Hope that helps! Feel free to reach out if you have any other questions.