Making your own Colloidal Gold is very easy, and several methods are shown on this forum. I make and take colloidal gold for my autoimmune condition caused by the Lymerix vaccine. Its quite possible to make 100ppm colloidal gold, but its not very important whether its 50 ppm or 100 ppm. What is important is how many milligrams of gold is taken. You did not say how much you take.
A 10mg dose (250ml of 40ppm Au) of ruby red colloidal gold costs about $1 to make. You can also buy colloidal gold tablets containing 10mg of gold for a reasonable price. Most of us here make it ourselves either through electrolysis, or the reduction of gold chloride (easiest and best). Making it with gold chloride requires no special equipment, and takes only minutes.