I have a client that is interested in purchasing a commercial building utilizing funds in their IRA.  

How much will it cost to split out those utilities?

The biggest issue we have is they cannot produce original receipts, so we have no idea what is a real charge or an upcharge.

The investor will clear land, install utilities and likely double his money. 

Thank you @Michael Plaks  I use the online version and do utilize the automation of pulling in the data.

@Daniel Mendez my advice I give to anyone looking to utilize the BRRR strategy is to make sure your final R is locked in place.

The only shared utility is the hot water . 

@Blane MorganThere are alternative structures providing checkbook control that do not utilize a LLC, which will be much more beneficial to you as a California resident. 

I then went on to use it as a successful income producing property for the next 6 years, bringing in roughly 26-28k a year in annual gross rental income. 

When you make an offer and you have that inspection contingency time, that is a good time to get the GC in there officially with a more detailed estimate based on the scope of work that you would produce for them.I can't urge you enough to read books and study spreadsheets (a bunch of them here on bigger pockets).