I wouldn't let the crummy Massdrop comments on the Lasmex scare you away....there just aren't enough reviews of them to really come to a consensus. I have read through a lot of that Lasmex thread and it seems like there are a few people that are all bent out of shape about the fact that you need to EQ them to get the best out of them...well, guess what, below $100 nearly EVERY headphone needs mods, or EQ or both.
For an open backed sub $100 headphone my favorite is the Phillips SHP9500s ....but I don't know they are priced in your country, I think in some places they can be over that price.
The other budget open backed I like is the Superlux HD681 (the original 'red' version) It's technically a semi open backed, but with some very simple mods it is easy to give it a little more open sound. If you get the 681 replace the crummy stock pads with some Senitek Hybrid pads. Even with the pads, you should still be well under budget, and it's sound quality is hard to beat without going way over your budget.
Ha, ha I had both the Superlux and Philips in the past and sold them off also (done that a lot LOL). IIRC, I put velour pads on the HD681s to improve comfort and it killed the bass and accentuated the treble making them ear daggers. Seems like I liked them pretty well sound wise before the pad swap. Couldn't wear them long though because of the sweaty stock pads. Have you tried the HD668B? They get good reviews. Then there is the EVO series. Too many choices!