Most skincare companies raise their prices annually or bi-annually. Decleor has gone up this year again, but it's not affected my sales. You have to be careful that you don't project your opinion that it's expensive onto the client when selling it, as that will come across.
To be honest if you work out how long the average professional moisturiser lasts (in the case of Decleor about 4-6 months) & divide the product cost out over that number of months it normally works it the same if not cheaper than buying the lower priced high-street brands on a more regular basis.