most recommended headphone for ~70$?

Another +1 for ATH-M50s. Seriously, you'll probably end up throwing away whatever cans you get for 70$ after a couple months....you'll just end up spending more in the long run, maybe.
I say save up and get those M50s.
 
For that budget I'd recommend maybe something by behringer? They usually punch a bit above their price bracket and you'll most likely be replacing them in a year or less anyway.

Seems like there's a quality jump around the 160 euro/200$ price bracket and everyhting else below that is significantly worse. I went for ATm m50's myself and think they sound great, better than any other phones I've gotten to try around that price.
 
and what about the ath m40? they are the same price tag of the sehneiser m250.
i think i wont be able to buy anything on the 200$ market, not sure about the long run though, because i always try to avoid mixing with headphones actually..