Risky First Venture?

[Eric Lunsford]

Hi y'all! I've been perusing for awhile now and have been doing some research on buying and holding properties to increase my wealth. This is primarily to build equity at this time but I'd love to be able to "retire" early from my career in the next 5-10 years and live off of positive cash flow while continuing to invest. That said, I have never invested in real estate before. I've purchased and sold 3 homes (using a realtor as well as buying/selling on my own). I've also owned a rental (I moved from my primary residence at the time.) 

My plan was to start small. Save up some cash for a downpayment and some rehab and start slow. That said, there is a house right next door to me that has been for sale for a few months. It's a huge house (~4500 sq ft. 5 bed/2 bath) early 1900's mansion. It seems the house is in good shape, just needs cosmetic work and a new roof. 

There is also a carriage house in back that is currently rented and has a tenant for $550/mo. 

I believe I might be able to borrow a DP and rehab costs (~$75k) from a hard money lender. The listing price right now is $259,900. It's a shot in the dark, but I know the guy is single and works out of town and is wanting to move. If I could get him down to $185k - 200k I think I'd be able to rent the whole place out for $2k/mo at least (including the current carriage house rental). 

I would plan to buy using the hard money, rehab, and then refinance. My primary residence right next door was purchased for $260k about a year and a half ago. Zillow says it's Zestimate is abut $300k+ now. It says this house for sale is about $255k. Similar houses in my small town per square footage have sold in the past 6 months for around 300-400k. 

Calculating all costs (I would manage the property myself since it's next door), I am thinking with the refinance mortgage of about $1000/mo and rental of $2150 I could possibly be getting around $700-800/mo positive cash flow. Not to mention I would pay the hard money loan off in a year while making monthly interest payments with the cash flow and then cash out with the refinance would pay the balance and allow me to walk away with ~$15k check. 

All that said, am I possibly going too big too soon? I've been thinking about a 50-100k mortgage on a house worth 120-140k...not 300k haha. 
Any advice would be appreciated. Just looking for some expertise and maybe experiences from this group. A ton of knowledge here! If I missed an important detail please let me know. 

Thanks,

Eric