Until the Canabis Control Act is gazetted, and given the current political climate that could be months or even a year or longer, predictions on the retail landscape are challenging. And once that act is gazetted it will take a year or two for all the government organizations empowered by it to issue regulations.
Maybe there will be brick/mortar shops in tourist areas selling to short-time visitors. Like the Cannabis Sandbox concepts thrown around by some government officials?
For Thais and resident aliens I think we'll continue to use on-line ordering. Right now I'd guess that 80% of sales, by volume/revenue are from on-line. Why do I need to go to a shop? I can watch bud porn at home.
Regarding prices, the market is quite young and not really subject to the usual rules given the pent-up demand, and supply (lack of? or too much).
In my very limited experience, stocks sell out quite quickly, hours in some cases, at current prices.
But there does seem to be too much dirt weed, and wholesesale prices on that have dropped by ~ 25% since 9 June. That "weed" will soon be 1,000 baht/Kg, in a BOGO scheme. Or it will be used as a building supply?