Steel prices jumped 40% in under six months during the last major supply chain disruption. Lumber and concrete followed. If you've been burned by price swings between bid day and delivery, you already know what that costs. Pre-purchasing materials by locking in prices by buying early is a smart hedge. But it creates accounting problems most GCs aren't set up to handle. Misclassified assets, missed write-downs, and sloppy tracking can erase every dollar you saved and create re