Many sources of Saw Palmetto are available, I think PropeciaJunkie has one of the cheapest :bravo: (damn being in the UK without a Walmart!!)
As I said elsewhere, more is not necessarily better, you can also get Saw Palmetto with other ingredients that might also be helpful to you, I've been doing a lot of looking around, and have to say Provillus is very well advertised, but has much less postive feedback than some others.
Big 3 are the way forward, especially Minoxidil (few side effects, not often felt). The FDA has approved it and Finasteride, and nothing else, for a reason, they really do work, so whilst experimenting with Saw Palmetto is great (I'm thinking of trying it as well) use it alongside a traditional treatment to be safe!
I also use a concealer whilst my Minoxidil treatment is working (its a slow progress job!) Dermmatch and Toppik are 2 of the biggest, personally I'd reccomend Dermmatch & Nanogen used together, works really well!