This has been talked about in a few other threads, not this paint per say, but that BASF has canceled the production of Irgaral. When they bought the product, they did not reup the tests etc to keep it in production for bottom paint use. Depending upon the where you get paint, this may go away in a hurry. WM for the most part is sold out, OR< it is under lock and key to go to the yards that they sell to wholesale only.
So the answer is yes, limited supply, if you can find it, great, if not, your screwed. Within the industry, there is hope BASF WILL put the herbicide back into production after going thru the testing with the FDA?!?!?! iirrc. This could take 6-12 months before back in production etc. So as noted, all of the manufactures have started putting in more copper, which is probably why the paint is costing more. Some have gone from 40 to as high as 47-48% copper, paint has gained 4 lbs of wt due to the extra copper per gallon.
Marty