I started by doing joint ventures with homeowners, contractors, investors, etc.

I forgot to replace the missing plumbing :-)Held me up a week; lesson learned.

But with construction costs skyrocketing and considering how every good contractor is booked for 6 months, you'll end up getting quotes closer to $250-300/sqft.Generally it is not a good practice to estimate the ENTIRE project based on price/sqft, as some items are way more expensive than others, but you asked for a "general" ballpark.

hello everyone in the BP community my name is Marcus and im in the upstate Greenville SC area and have been researching real estate investment for the last 5 years and have also put in a few offers I am extremely interested in multi-family Investments and building up my rental portfolio I am an HVAC contractor and would love to help the BiggerPockets community in the upstate area and also learn from the veterans of real estate investing.

If there are roads or utilities completed (horizontal development) were all those contractors paid? 

Any advice on either when in the process or how to start contacting contractors?

@John Hein make sure you pinpoint your ARV probably wouldn't be a bad idea to get a contractor in there as well to give a rehab estimate if you have time for that.

If there isn't a problem with the plumbing, I would say this is just another issue with investing in MFRs.

Only inside needs to be gutted (new electrical, new plumbing, new flooring , the cheapest flooring) Can you guys let me know approximate numbers?

@Amdrew Polinchak I would primarily focus on having a fantastic relationship with you contractor, that is if you're not your own contractor.