I want to do this the right way and I want to make sure that I have enough saved up to start a good direct mail campaign and be consistent with it. 

We were initially paying him $4k a month with the plan of giving a bonus at the end to compensate the extra work he did.

We work with a lot of very successful investors and one thing that sets them apart from others is being consistent with mailings.

University areas are great because of the consistency of tenant availability.

None of these are consistent and I've been lucky enough to live by them so far.

But you really want to set yourself up where you can afford to do it consistently.

Just tell them you're asking because you've run into problems with low appraisals and if they use the same appraisers, you won't waste their time with an application.Also, it isn't imperative that you use the same one's, that's just a bonus.

Stay proactive, if you stay consistent, things will happen.

Just be consistent and mail to your list many times (as @Claire Trammell says) over, say 5 to 8.  

My dad bought a house in a C+ neighborhood and has had to re-tenant it multiple times because of tenants consistently paying late or not paying at all and leaving in a few months.