I'm from Russia. When importing goods personally by air (plane), the limit is not more than 10,000 euros and weighing no more than 50 kg. Personally, by land transport (train, car) or on foot-the limit is not more than 500 euros and weighing no more than 25 kg. Goods by mail from an online store for no more than 200 euros or 31 kg per parcel. The customs rate in 2019 was 30%. Now (from January 1, 2020) the legislation has changed and the rate is 15% over the limits. (For an additional kilogram over the limit of 2 euros).
But bro, it's not the best idea to make money. We do not have an Apple representative office in Russia, but everything is sold officially. There is no shortage. You may face implementation problems and crime if you plan to sell in person.
You can just come with dollars, exchange them for rubles, buy with this money in Russia what is produced here, but is valued at home, bring it to you from Russia and sell it at home. Then you can get a good raise of money. (The dollar exchange rate in Russia has increased 2 times since 2014. Until 2014, $ 1 = 30 rubles. Now 1 = 60 rubles). It is because of the exchange rate that all imported goods have risen in price by more than 2 times. Think about it and don't rush your idea. Just think well! Good luck!