Should I sell it to a cash offer company?

I've had 4 different local RE agencies assess the asset at €580K, €650K, €730K and €800K. 

Searched four sites and came up with a different decision than your original decision to go with them. 

I put some numbers below into this Rent or Sell calculator.https://www.narpm.org/members/resources/rent-vs-sell-calculator/ESTIMATES ON ROI (15 year time frame)at 5% Appreciation would profit $100K if SELL nowat 6% Appreciation would have $3,500K more if KEEP and sell after 15 yearsat 7% Appreciation would profit 122K if KEEP and sell after 15 years(Assuming a conservative 6% ROI on money invested from sale.)NOTE: The property appreciated 10% in the last year so I’m thinking 7% over the next 10-15 is reasonable.DETAILSSale Value: $520,000 (Best guess)Paid: $437,000Original Mortgage: $415,000Mortgage Balance: $380,000Interest: 3.375%Monthly mortgage: $2,899Mortgage Difference: $1064Annual Taxes, Insurance, HOA etc**: $20,345**$13,865 (Non Homestead tax) $4,680 (HOA) $1,800 (Landlord Insurance)Monthly Rental Charge $3,500*Appreciation 7%Years to Hold: 15More assumptions used in ROI Estimates Above90% occupancy,15% capital gains charge6% selling feeRate of return on gains if selling now instead 6%Annual maintenance 1%Annual rent increase 4%$3,500 is slightly aggressive. unlikely I could get more.Thanks in advance for any constructive thoughts and comments!!!!

@Spencer CuelloI would google 506 B and syndication companies.

Do you have a different perspective or advice to share?

If the property is homesteaded, you are grandfathered only at max 3%.You can see bellow an example as the taxes increased after the change om ownership. the big difference is due to fact the area appreciated 1000% since the 90s when the house was initially purchased as a homestead.

My company is one of the sponsors for the Raleigh REIA (Real Estate Investors Association).

Quick question about property management:In your opinion, is it better to hire a property manager (pay about 7-10%) for a company or use a software system to save money ? 

If you need, I have a good atty and title company for upstate NY, PM me for info.