I have a single family 3 bed 1.5 bath home located in Bellevue that I'm trying to finance.

I recently had a seller tell me the house was a 3 bed, 2 bath.

SI is pretty cheap compared to brooklyn or Manhattan, so many people are willing to trade longer commutes for less rent ie 3k/month rent for small 1 bed 1bath in Manhattan to 1k/month similar size apartment in SI.

I found a nice duplex for 120000, good location.one side is 2 bed 1 bath, other is 1 bed 1 bath.

The house is a multi family home built in 1900, 4 beds/2 baths, 4,000 sq ft lot, 1,500 sq ft, was last sold for $69,000 in 2003 and currently has an estimated value of $79k. 

A 1,432 sqft, 3 bed / 2 bath single family home was just listed today in an area that rents for around $1,200 a month.  

I have a single family rental (2 bed/1bath) in Berkeley, CA that I bought in 2013.

First, what are the bed/bath count?

The house is a multi family home built in 1900, 4 beds/2 baths, 4,000 sq ft lot, 1,500 sq ft, was last sold for $69,000 in 2003 and currently has an estimated value of $79k. 

Try to look for homes that have sold in the same area, with same square footage and beds/baths.