Hey @Jonathan Tran, I'm just a rookie so take this with a grain of salt.If property taxes are the biggest factor in your choice of farm area, there are better states to pick. 

Just listing a few factors that are kind've important .

I think it's better to use the extra money for a future property, but your comfort level should be a factor as well.ADU is a good idea if you're going to live there for awhile because it's one of the only ways you can run a short-term rental on Airbnb in Denver full-time.

. * Don't allow financing or a finance contingency (it can be a good indication they are selling above market value)* Don't allow for your own independent property inspection* Are not realistic with their pro forma's (i.e. they don't include vacancy or maintenance projections or use      unrealistically low vacancy factors)* Require you to pay for any renovation upfront* Sell only in cheap. low end neighborhoods* Don't accurately represent the neighborhood/property classification* Don't have consistent rehab standards for all properties* Don't provide a scope of work for the property* Can't provide references of repeat investors* Require you to close before a tenant is in place

When you factor that stuff into the equation the cash-flow changes.

On the surface, and as Andy mentions, that's seems too good to be true, so there is likely some underlying factors not divulged.  

And if that is the plan then you should factor that in your analysis and make sure the numbers still look good even in that scenario. 

They gave me a written estimate including what they called a "fudge Factor."

Therefore not only do you have to factor in the money to correct this issue, but also the time spent overseeing the project. 

My experience of human nature is that if he already has the money, he's less likely to be concerned about his performance and if we're happy with him or not, etc.Another option is to wait until the summer months where the service calls are 3x/month, and then let the vendor opt to take the $550 average per month - that way we have the leverage if he decides to quit early or if we're not happy with the work - if anything, we would owe him money instead of him owing us service.So one factor is who has the leverage.The other factor is if there's a benefit to having the monthly costs consistent every month - does this matter to you as an owner / property manager?