Its not because of demand and supply, its because of lack of fair access to bitcoin trading market. On 15 Dec 2019 (date of this post), price of bitcoin was 7100$ while in Venezuela its $9500 on that day. If people in Venezuela have access to large exchanges like coinbase, they would have easily bought at 7100$.
I think it still counts as law of supply and demand. The demand is high but the supply or the fair access as you mentioned for the market is low that's why they are at the premium price now. Some people there probably have internet connection and they can easily access to the web and trade as much as they want but their money is becoming useless due to the hyperinflation.
Calculating the venezuelan bolivar they have wouldn't count that much even if they want to buy bitcoin because the exchange rate for $9,500 of bitcoin is with (USD/BTC) and you might barely find someone who's willing to trade their btc's for bolivar. I think there are few wise folks there that are making this is as an opportunity to arbitrage but don't want to be exposed as they might get tracked down. I don't know the policies there currently but there's a tendency that it's like that.
