how to reserve train tix Budapest - Targu Mures or Cluj, Romania

The most good i am going to do here is keep you bumped to the top. For the schedule, have you been to the website? Elvira is not only the mistress of darkness but alos the mistress of the Hungarian railroad schedule http://elvira.mav-start.hu/elvira.dll/xslms/index?language=2 They generally only post schedules a few months in advance. Yes, not good. I've taken the train from Vienna to Budapest and the train from Budapest to Eger and in those two short encounters and in conversations I have had with others that know a lot more than I do, it is my understanding that you will have no trouble purchasing tickets a day or two prior to departure; or even the day of departure. Apparently the trains dont generally sell out and if they do there is another one right behind it. Also, apparently, the seats are all first come first serve so its just a matter getting to the station a little early. At the very least i have provided a lot for someone else to correct. But i feel pretty sure I am 90% on the mark. Also, it is my understanding that you will get better rates a day or two before departure in Budapest. Sorry, wish I had more.

MAV (the Hungarian train company) has special fares to Cluj. Unless you are travelling at a particularly busy time, it shouldn't be a problem to book a ticket the day of (Pentecost is the next big one I can think of). Here is a link to the Cluj specials (Kolozsvár is the Hungarian name for Cluj Napoca.) The site is in Hungarian, but Google Translate does a pretty solid job. http://www.mav-start.hu/utazas/kulfoldi_utazasi_ajanlatok.php?mid=14b165eba8acf9

how many days are you in budapest? if more than 2, why don't you just buy when you arrive? the international ticket window is downstairs in the main train station, and there is also an info desk up stairs you can have them look up the schedule. the trains are very frequent, so there is no need to buy online.