To section off or not to?

[Maciej Kupiszewski]

Good morning! Please excuse a basic question but thought why not seek input from the right place.

I own a 1 bedroom coop (700 sft) in Forest Hills, NY (Queens) - about 1 mile from subway stop which I'm getting ready to rent out. I met with a broker yesterday who will do the legwork and one of the first things she threw out when in the apartment is that I could convert a part of the living room (L shaped), into a small bedroom to basically get to a junior 4. she thought that would raise the rent potential by about 100-150 monthly.

This made me think whether I should jump in and get this done before putting on the market. When I originally bought the coop the wall was in fact there and I had it taken down because I personally wanted an open floor plan. 

Using very rough estimates, if the cost of the job would be $1,000, and there is a month delay in getting it rented out due to coop approval process and the work,  that's another loss of 1,650 income to replace with $1,800 income. Theoretically from a demographics perspective someone looking with a junior 4 would be looking for that because of the family needs which feels to me like it could translate into a more stable tenant and less vacancy than a single professional. do you think its worth the investment at this time? I'm keeping a 3-5 year window as a basis of my decision.

much appreciated,
Maciej