Flown the Frankfurt-THR route. In my experience I have never heard an airline flying to THR cheaper than Iran Air does and the pilots are obviously very skilled. But there are negative sides to flying Iran Air. First of all although their Aibus fleet is one of the safest in the world their other aircrafts (Boeing747(SP)727 and Russian aircraft) are one of the oldest and most dangerous - so my advice try to avoid these aircraft when flying Iran AIr. Luckily most European flights are with the Airbus fleet. I also know that the poor shape of their Boeing fleet is not caused by neglect but the fact that the Iranian government can't buy spare parts for these aircraft from the US (politics and stuff). Also inflght entertainment is almost non-existent (not even in their Business class) especially if you don't like Farsi spoken movies shown on a projector so bring a book/magazine/walkman or whatever. My advice is to fly Iran Aar if you are sure that they are using an Airbus aircraft and if you are more concerned about your budget then about stuff like inflight entertainment or alcoholic drinks.