When comparing EPS box prices, first confirm that quotes describe the same product. Internal and external dimensions, usable volume, wall thickness, lid fit, product code and order quantity must match before unit prices are comparable.
Ask each supplier to separate unit price, minimum order, tooling or setup, packing, freight, lead time, delivery and tax. If material density or performance is declared, ask which test and sample support it; do not assume standard values.
Obtain a sample and assess it with your real product, coolant and shipping arrangement. Record damage, lid fit, internal volume and measured temperature result. Decide using both the total delivered cost under matching terms and the trial result, not unit price alone.