It's 30% but that's off the MSRP and that's what they charge when you buy directly from BM.. In all cases, despite the discount it's still "much" cheaper to buy from my regular dealer..
However, when I was active and used to order BM knives in my official capacity for my armory personnel threw the stock system utilizing the NSN number I believe the price was reduced and of course tax exempted.
If it's for you personally then you don't save anything using the 30% discount. In fact you still pay a lot more. Better as I said to go threw one of the well known dealers.
If you are trying to order for your department, call and see what he prices are and it may be cheaper, especially if you are buying a large quantity as I used to. It's been many years since I ordered BM knives threw the stock system so thing's may have changed as far as deals and prices but you can always call and ask.
A five minute phone call will probably answer all your questions.
All the best! .