Now this was two years ago, and the rent has gone up to $1250 with 2 of the 3 students staying with the house and splitting the rent even with the price increase.

Because once you stabilize the property, you will have created massive equity and drastically increased the cash flow.It takes anywhere from 6 months to 24 months to stabilize a property.

The tenant also has an option agreement where they pay me $20K as an option consideration to purchase the property for $200K in 3 years. 

You need to figure out what the market rate is, and for sure with every vacancy increase to the market rent rate.

Hello everyone,I know for determining ARVs it depends on a variety of factors (area, neighborhood, condition, comps, etc) but from what you've noticed in your own personal deals and the final appraisal what are some things within your control generally to increase ARVs?

One of mine was $5200 a year for 11 years and increased my tax burden $13k. 

Yes, although the prices has increased very steadily so I think there are better opportunities elsewhere.

Kai, I have a 12 unit as well and have been wrestling with the same considerations-value add and generate more rent.

I guess the reason they've captured some interest is because of their increases haha

I would not take into consideration 1 of the 2 being vacant.