If you're ordering $100,000 worth, why aren't you ordering direct from the manufacturer? - a distributor (like Arrow - and as they said) probably aren't allowed to give massive discounts, and would presumably loose money if they did?.
Luckily, quite often, when you buy parts from distributors, the actual manufacturer is listed on the item - so you could always try contacting them directly. We've done that in a number of cases, and managed to make substantial savings.