There is another popular one called VRCalendarSync.com I believe that you can purchase the premium package and it will do everything for you.  

(if you buy the middle package... you get 3 sites... and you need the middle package regardless, so you get your buyers site for free)

Number of packages/letters processed?

The BiggerPockets package has inspection forms, pet forms, application, etc. 

These companies range from 4K-12k for their packages.

It would be cool if the plus package included a 1 month free pro membership or something.

In practical terms, an example of what that means is that 3-4 months before your BRRRR appraisal (when you're still doing rehab work), start visiting the open houses of all of your future comps, get the seller's disclosure packages from listing agents (pretend to be an unrepresented buyer if that's what it takes), and find out in writing from the seller of that house why that comp is about to sell for $50k or $75k less than what you think your property will be worth.

I am also seeing many smaller boutique funds starting up SFR plays and then packaging and selling to HFs which might explain why some folks think they are gone from the market.

I currently own/operate 4 properties with a total of 23 Units and I just took a separation package from my main job. 

Our original intent was to package four of them into one owner finance deal that would help him have passive income for the next 10 years, however when we could not come to terms on the details of the deal, we pivoted and found a private lender who we also had a relationship with, for one of the properties and negotiated a price under market value.