Your plane flight there will probably be about the same, although cheaper fuel could lower this as well. However, when you get there everything is now 50% cheaper than it was this summer. The ruble traditionally trades around 30 to 1 US dollar, but now it's in the lower 70s for 1 US dollar. Some analysts are expecting it to go to 100. I don't know, but regardless it's still really cheap now.
Most of this stems from oil prices being severely depressed. Half of the govt's revenue comes from oil and when the price gets cut in half it obviously will cause a serious problem. I don't see this situation turning around until the price of oil does. I'm not sure when that will be, but I am pretty sure that it will eventually.
In the mean time if you want to invest there do it cautiously. I'd recommend investing in an ETF rather than individual stocks. Russian politics is highly volatile so it's not uncommon for them to take a company or radically change a market through regulation. Russia has been around for hundreds of years and has been through this before. It will survive, but the question is when will it turn?