The OP did mention this is a SFR, so no other units, which obviously makes this consideration more important.All that said, viewing this as a cost you should or shouldn't undertake due to how many months it takes to recoup is, IMHO, the wrong way to view this.

In my opinion, NPV in and of itself isn't enough of a financial measure to determine whether a particular project is worth undertaking...First, it doesn't factor risk into the equation (and no, you can't just increase the discount rate to account for risk, it's not a linear relationship).

The "kick 'em all out" strategy carries more risk that I'd prefer to undertake (and is usually a strategy in a D neighborhood which I'd rather stay away from).

It sounds like a big undertaking being so new and still reading books.

I think the reason I am so comfortable undertaking this at this time is because my base is so solid, my families living expenses are so low.

I'm planning to make a nice graphic to throw up on the site.  

Assuming that you are wanting the service to create, print, provide postage and mail then.....Click2Mail has the cheapest prices and quickest turnaround from my experience.But, their software is horrible and so is their quality.They're fine if you're just using text but if you use graphics then be prepared to send out wimpy card stock with smeared, smudged and blotted art.

It's a huge multi-billion dollar undertaking that is projected to be finished by 2030.

@Brian G. trust me when I say that I think it is an awfully big project for my first undertaking as well!  

@Dev Horn props to your graphics department there.