You can outsource your accounting department or just partial work.

I've been DIY on the turns to control costs but it's also costing me time and stress so I was interested to see what outsourcing that would cost.

I love SFHs, and that's what I deal in, but unless you are going to outsource most of the work with property management, 50 SFHs is easily a full-time job, even with the easiest tenants in the world. 

Is the management the same company as the turn key company or outsourced?

Regardless of the nature of your business, it is critically important that you maintain accurate and up-to-date financial records. Managing your books will not only help to evaluate the performance of the business but...

As Andreas mentioned, it's good policy to outsource your debt collection activities to licensed 3rd parties to reduce risk and stay compliant with rules and regs.

For fulfillment you can do it yourself to save money if you are broke, but ultimately if you want better response rates and focusing your time on value-add, then you will want to outsource fulfillment to a shop that has economies of scale and can offer you great rates.

Outsource tedious low-value added activities but make sure you do the important ones yourself.

@John Zhao This is one area that I wouldn't try to outsource to the BP community.  

I will also be getting my real estate license to save on commissions and we'll outsource the contracting and other work.Our goal is to purchase a property by the end on 2018 under a corporation and to have no personal debt since we prefer to have no debt under our names.