have to look at how much it will cost you to get in . how much will cost you to build . how much it can be sold for 

I've got some leads on nice houses, but I don't know the neighborhoods.

The dilemma i have is that I can’t decide if it makes more sense to embrace the c class identity this property gives the impression of, or put a lot more into the renovation, get better quality tenants and convert it to the B class property that the building (and the area) should/could be. 90% occupied, the yearly rental income is around 600k with 420k NOI. 

Build the secondary units and legalize them, then refinance with them in place.

With that said, Bryan is spot on because you get those rents are in the better neighborhoods in the east side of town 31907 area. 

This is a B property in a good neighborhood.

The first step to building your REI empire.

By putting 10% down I probably will be less than breaking even every month ((like an extra $800-900 per month at very low/conservative rent prices)  with the building fully tenanted (as is condition not counting value add with renovations). 

I wouldn't rely on information here as we haven't seen your building nor understand your bigger goals but this is not something I ever recommend my clients to do....even if they have a few deals under their belt.

how do you know if a neighborhood has potential of going up in price?