I have an Industrial account with Snap-on and my apprentice is also eligible for the student discount. Depending on items, we typically pay 35% to 50% off of list prices.
Occasionally there is a difference between the student and Industrial pricing of an item, but as we don't usually buy big ticket stuff, it's a couple of dollars here or there.
There is no limit to the amount my apprentice can buy and he can order discounted tools as long as he remains a student tech.
There is no Matco presence here, but Mac also offer big student and corporate/government discounts. For students buying Mac, it is a 1 shot deal. You get 1 order which is discounted (99.99% of it anyway) at 50% off. There is no limit to order size, but you can only order 1 of each item.
I'm sure that these discounted tools do yield a profit (or at worst are marginal) for the manufacturers. You have to remember that it is their biggest customers who pay these rates for the tools! I'm sure there is more revenue for Snap-on from corporate enterprise and government customers than there is from individual techs. If someone has the numbers to confirm or refute this, I'd be interested to see them.