How to Comp a Duplex/Triplex in Small Town America

Hi, my husband and I are looking at purchasing a SFH that has a layout conducive to converting it to a duplex and possibly a triplex. Each unit would have 1 bedroom and 1 bathroom. We are hitting a road block on how to comp it for resell if we decide not to rent it out ourselves because it is in a small town. There are a handful of multi-unit apartment complexes, but I'm just not sure how to go about determining ARV since there are very few duplexes/triplexes period in the area. Should I comp it out like a 3 bed/3 bath SFH? Any guidance is greatly appreciated!