Gold jewelry should also be left at home. You will likely be asked to count all your money in front of the customs officers, both when entering and leaving the country. The amount you leave with, plus purchases you have receipts for, should match the amount you came in with. The current exchange rate is about 5,000 rubles to the U.S. dollar. Handheld two-way radios are restricted.
Airport security is generally quite good.
Leave as much as you can in the airplane and only go through customs with what you need for your overnight stay. Itemize and declare valuables such as cameras, computers and personal electronic devices. Don't buy these items, even though they may be perfectly legal in Russia. The pilots in command of private aircraft can be held responsible for violations by their passengers or crew, which can result in seizure and loss of their aircraft, as well as large fines and a possible jail sentences. All this can be imposed for something as small as a pocket-sized ivory carving.