Is this deal good for Rent-by-Room?

[Kat Hussey]

Hello! I'm looking at a property that's in a great location, but the rents in the area are just a little lower than makes sense. However, this area is very close to downtown and I think could be great for a rent-by-room property for young professionals. How does one run rental comps for this?  

Does this deal make sense and seem like a good investment if it works out for the added bedroom/lot unit?

Details:

3bed/2bath (potential for garage conversion to a 4/3 or 4/4 depending on floorplan)

1300 Sqr Ft

2 Driveways

Year built: 2000

From what I can tell, it only needs minor cosmetic updates, but I'll get an inspection after under contract.

Listed at $339,000 (DOM: 83, so I could probably get it for less)

There is also a small lot next door that I could build one more unit on, possibly a tiny house. This would make it a 5//4 or 5/5 total for the property & lot. The lot is listed at $95,000

Rent for 3/2 in area: $2600 (plus extra unit in back for $1025  = $3625)

Rent for 1/1 in area: $1025 (x 5 units = $5125)

^these were the approx. averages from rentometer.com.

I'm thinking I could offer $380,000 for both the house and the lot, then buy a tiny house for approx. $60,000 for the back lot. All-in: $440,000