Not sure if this would be worth it for us to buy

[Shenell Caldeira]

My husbandʻs grandmother wants to sell her home on the Big Island of Hawaii.  She has a little over 2 acres with 3 permitted homes on them.  2 of the homes need to be rehabbed as they are not livable, we came up with probably about $180k in renovations.  The main house is older, it was bought in the 50ʻs, there were some additions added to it but everything inside is original.  We would love to keep it in the family, try to renovate the 2 homes to rent them out long term and the main house slowly work on upgrading and then eventually renting this one out too.  

Iʻve been watching videos, going back and forth on the calculators, we didnʻt expect this to come up as an opportunity for us, but the biggest thing is she will want market value for it and if we canʻt do it, then Iʻll list it on the MLS. We want to come out of this with little to no money out of pocket, but we may have to. Does anyone have suggestions as to what to do in something like this? We donʻt want to short change her and low ball my husbandʻs grandmother as she is using this money for her retirement home that she and her sister will be living in on the mainland.