I agree with KO. Banned but rarely enforced. Please note that it isn't defined what is "personal use." Nobody knows what it means and an amount is not defined in any law. A border guard from Finland and Estonia may say it is $100 Euro. But in reality - if you had to stay in Russia for a week or longer, that amount isn't enough. All I can say is - if you are asked by any country how much of some money you have, just tell them the truth or risk penalties and possibly detainment.
The way around this mess is to simply convert your money to US dollars before crossing over into Russia. Then go to any bank inside Russia and convert them to Rubles or Euros. The European Union has no ban on USD entering Russia. Very large amounts of USD need to be declared at the Russian border. A few thousand - no. But the first country may ask to see what you are carrying.
One time I went from Estonia to Russia and I wear a packet around my neck. She asked about money and I pointed to my chest and then she wanted me to undress. So I just opened 2 buttons, took out the pouch, unzipped it and showed them the money. All mostly USD, some Rubles, and about $50 or $100 in Euro. They were fine with that and they didn't even bother to count.