I suspect you return is much higher than you indicated.You have incredible prop 13 discount by now.

I recently purchased a property that includes a 3-bedroom, 3-bathroom main house and a pool house that can be converted into a 2-bedroom, 1-bathroom unit.

We re-did the old bathroom and added a master bath with the master suite.

They are willing to sell the property to me discounting the realtor commissions after the contract with the selling agent is up.

He must have a stack of JV agreements in the bathroom just in case he runs out of toilet paper. 

Purchase price: $115,000 Cash invested: $35,000 Sale price: $240,000 Move in ready, fully renovated townhouse, 2 bedrooms with 2 1/2 bathrooms and ample closet space including walk-in closets in each master bedroom.

once you actually identify a specific property, you need real numbers.in a duplex you may have two of everything (unless some utilities are shared) - two furnaces, two water heaters, two sets of appliances, lots of bathrooms. 

I'm a newbie trying to rent out rooms in my 4-bedroom, 3-bathroom house in Seattle.

Hopefully she provides the receipt but if not you got sufficient discount to be acceptable.This is not a big enough expense to be bothered by.  

The rent usually increases, but I give a discount for signing a new lease.