Not sure what else you are including (disp. chafers, plates, utentsils, cups, linens..etc.), plus are you smoking or grilling those ribs. Are you providing buffet or serving. How many helpers? Travel?
If this is a good customer and you will get the other two parties, I would do this for about $14 - $15 a person. The ribs are definitely going to be cumbersome, but the rest all looks like cake.
BTW - If you are serving full spares (not st. louis) I would do 2 maybe 3 ribs per person. But then this will means that you will need to serve for portion control.
Diamond Plate FAT 50 Ultra
55-Gal Horizontal offset
2 55-Gal Vertical Barrels
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