They do exist, they just require either a vast amount of luck or time.
I was the dummy who decided at level 15 that I wanted a fully upgraded set of WB armor. Well, actually a friend talked me into it, so we all went together over, and over, and over and over. In the end, I got a full Ventis Archmage set that lasted me til I upgraded to Evil Dragon from Kalin Shrine at level 50 or so.
I used to farm the windmill obsessively to make gold (OD pieces of the blue base gear at least used to sell pretty well and they are unbound), and because I had a guild full of lowbees that needed good lowbee gear.
I can't even begin to calculate how many hours I spent inside the WB, but it was many, many, many. I could still navigate that place in my sleep. I have personally gotten about 5 of the rune crystals and I bought one here and there when someone put one in the AH.
I have made a total of 4 sets of the purple upgraded gear, and I have to say, when you get it done, you feel pretty satisfied, and the gear itself is great if you are a slow leveler. I was (this was well before Xaviera was introduced), and so it was a good investment for me.
If you are planning on rocketing to endgame, do not attempt this. You will outlevel it long before you have the matts you need.