But don't just buy on appreciation, that is just a bonus. 

@Becca Summers That's some great advice about the bonus!  

Free beer and crawfish was an added bonus too!

Bonus if they have a military discount.

With good small apartment complexes you can hire a good management company and offer them a bonus for leasing out units.  

In the end, the value of the deal comes down to a minimum, specific, monetary return, within a specific period of time.Here's an example:  I want all my cash back at refi on a rental$100,000              ARV in specific area based on Sales Comps$  80,000              75% ARV for refinancing$  75,000              Cost to buy/rehab$    5,000              Cash Out at Refi (bonus, bonus, bonus...)Here's another example: I want all my cash back at by the end of the first year on a rental$100,000                 ARV in specific area based on Sales Comps$ 80,000                  75% ARV for refinancing$ 85,000                  Cost to buy/rehab$      500/mo.           

Having bonuses for contractors that get work done ahead of schedule, and bonuses when inspections come back without issues.  

It is just an added bonus- The property needs to cash flow when you purchase.

My office is under the garage bonus room so I am undisturbed by my little kiddos during work time.

As for how much, if the potential lender has other investments (CD's, stocks, etc), I would try adding 2+ points of interest to what they're getting on best of those, and maybe a bonus or stake in the profits if/when you sell the property.