You could have negotiated to include the same number of 56 affordable units as a community benefit for the increased entitlement given to the applicant while allowing them to benefit financially from 154 additional market rate units. Maybe even go crazy and ask them to increase from 56 to 60 affordable units while still gaining 250 units at market rate. A WIN-WIN for everyone.
Adding density does not ease escalating housing costs, but does just the opposite, by driving up land values
The widening gap between housing costs and most incomes is caused by escalating land prices, not construction costs or zoning rules.