In the US tax handling of employee discounts at least on physical goods is as follows: if the discount brings the price paid below cost, then the below-cost subsidy is treated as income received by the employee.

Concrete example: Company sells widgets for $12, of which $2 is profit. Then as long as the employee price is at least $10 there are no tax implications for the employees. If it were $9 they would owe tax on $1 per widget bought, etc.

That said, some companies will pay the relevant taxes for you, or at least try to by guessing at your marginal rate...