Cost of land in new construction project

[Molly Bortz-Druffel]

I am a Realtor located in Cincinnati and I am trying to understand if there is a general formula to determine the percentage of the total budget that should be designated for land for a new residential construction project in a very well-off and established neighborhood. There seems to be a very wide range of list prices for land in this neighborhood (that is actually listed) and most of the lots are similar as is the zoning code, school district, etc.. And most of the land sold to custom home builders happens behind the scenes so I can't use those numbers because I don't have the total construction budget. And most of the builders stay mum when I ask. Can anyone provide any insight please? This makes it very hard to price a lot with a tear-down on it... I have spent way too much time researching this when I could have just deferred to the experts here on Bigger Pockets! Thank you!!!