Estimated development cost on 100~ units (800 sq ft each) and land cost?

[Shanty Wu]

I am working on developing a 60% Area Medium Income (AMI), all affordable for a residential building. I am sorting out the number of units. I contacted a handful of developers to get development and land costs. I found some land costs but have not seen any luck with the development cost for 100~ units. Does anyone have an estimate of the development and land comps? I reached out to a handful of developers and failed to succeed. The project is located in the South Seattle Rainier Beach area in WA. I would appreciate any help. I am working on the performa and am happy to share my learning.