This is the 2nd person to make this kind of statement. The chance for procs is no where close to 50% or 60%. This is like claiming buying fortune cards are a good way to make money because you bought 10 and happened to get a 5000g card.
The chance of procs are 15%. Each proc has a chance to proc for 15% up to 4 times. So we can assign an expected value (EV) of each Flask created as:
1 + (1 x 0.15) + (1 x 0.15^2) + (1 x 0.15^3) + (1 x 0.15^4)
= ~1.1758
Just to pull some arbitrary numbers from my server's economy, let's say the mats cost 250g to produce a flask of the draeconic mind, and it sells for 200g. The 200g flask can be said to have a value of 200g x 1.1758 = 235.16g. ie: Your still taking loss. Particularly when you factor in AH cuts and deposit fee's.
Sorry, I wasn't implying to sit on finished goods, that would be silly.
The vast majority of prices tend to trend down the further you get into an expansion, so it's not a good idea to stockpile anything born of the Cata era at the moment.
procne brings up a great point about cauldrons, and the subsuquent lowering of demand for flasks in general. So I ask: why, oh why, are these BoP? We can't make money off that....fail. Extra suck: in my 10 man group for example, we have zero alchemists (my alchemist is on a non-raiding alt).