Need help pricing massive job

Hello everyone, I’ve been in business about a year now, and am well versed in average sized residential jobs, but recently have been asked to bid 4000ft of shadowbox replacement 6ft tall. My normal price for 6ft shadowbox is 30$/ft not including removal/disposal. I’m located in the south, and I’m really not sure how to calculate this job. I know materials will be approximately 40k. I’m thinking bid around 24$/ft for everything. Input greatly appreciated.