@Wesley Stewart
Thanks for the info. I think the biggest thing to address first is that you likely would not be able to use a VA loan on this deal. VA Loans are intended for owner occupants and only useable for 1-4 unit homes. Unless you are able to split the deal up into individual units, it wouldn't qualify and even then, it sounds like there would be difficulty in financing the remaining properties.
For future reference, you can probably estimate 2-3% of the purchase price for closing cost (separate from your down payment) on the buyer side.
There are VA rehab loans but they have limitations and stringent paperwork to utilize. You would likely want to make sure you identify a contractor that has experience with these types of loans. You can call around to different local lenders to see if there is one in the area with experience.
You could reach out to a few local property managers to get a general idea of what the area vacancy rate is. Always be weary of the sellers numbers. “Trust but verify”
Find out what kind of work is needed for 50k. If it's bad/unloveable condition in some of the units it may be difficult to get traditional financing on them until they are fixed up. Having to go hard money on the front in with significantly change your numbers as the money is expensive to borrow. If you were to go this route you can refinance to VA after the repairs are completed (assuming whichever target property qualifies).