Background on myself:   I was hurt on the job as a delivery truck driver 5 years ago.

So, it's either RE investing or going to truck driver training school at 50+ because I hear they can make pretty good money. 

We are in the process of purchasing all the materials needed for this flip (construction to begin July 1) -- we will put in a box truck and will have available to the contractor so we are not keeping him from hitting his timelines.

I know people have flipped cars, trucks, boats... then to use the profit to invest in real estate? 

$5,500 is probably two years of your cash flow. i will second and third the gravel recommendations. had a 10 ton gravel dump truck show up for $500 before, so unless that's against the city code, i'd go that route instead.  

My ultimate goal is to have 5-7 properties in the next 10 years to “retire” from my 9-5 and manage my properties / have a food truck

They started trucking some dirt out and also digging further on the pond. 

Keep going, keep trucking and keep doing the damn thing, because that life you want is not out of reach.

There is an investment involved in a delivery truck and residential tanks, and he knows he's leaving a ton of money on the table. 

@Delbert Standifer My humble opinion here is that your “friend/mentor” just MIGHT be trying to pull the wool over your eyes. 1) Regardless of when you will “own” the house, you are buying a MONSTER of a problem.