I would recommend that you look into Gettext (http://en.wikipedia.org/wiki/Gettext). Using this will make working with multilingual websites much easier.
Though, adding this to your website might take some time, so if you are in a time crunch you can do a small update and your current system should work.
Instead of using TICKETS_CUR_RUB, use TICKETS_CURRENCY for example, then each language will contain the correct currency to display, i.e. Russian will contain rub etc.