<sigh> In the dim and distant past I used to buy Golden Virginia from the little yellow-fronted supermarket opposite MacDonalds. Also the 7/11 on the corner in Sra Song road near the night market. About 260 baht for a 2oz pack.
But that was about 2-3 years ago.
If you plump for the golden virginia light,its pretty much like amber leaf. (its also in a yellow packet)I've never managed to find amber leaf in thailand but i usually get 5 packs at heathrow,which works out roughly the same in price.
A good selection is available at both the Chinese liquor store (on Petkasem corner of the Night Market) and at the MiniMart near JedPeeNong Hotel. About 260 for 50 gm. Also rolling machines, papers and tips.