I trained using dermalogica products and have continued to use them and think they are great. If you have a salon and are ordering larger amounts its obviously more cost effective to become a registered stockist with them which costs about £3,000 you can then continue to train, get support and obviously really discounted prices , However like me if you use it in smaller amounts ive found the cheapest and best service has been from 'beauty flash' available online, I have been getting my products through them for a couple of years now with no problems.
Hope this is helpful X