@Makhul: Wouldn't it have been easier to just strongly emphasize that the buyer has to pay all paypal fees? Before the buyer accepts paypal as a payment method, you could open up a pop-up window that states his obligation to pay the fees again, so he has to actively agree on this point. You could also link to a paypal-fee calculation site. Again, I've made the experience that the majority of buyers are willing to pay the fees once this is pointed out to them. It's just a matter of how this rule is communicated via bitmarket and the sellers. And how it is enforced if the buyers is unwilling to comply. As discussed before, a rating system would help here, too. 
That obligatory agreement I think would work well, and I find it as the best solution to this problem. I've always made it clear in my automated mail as a seller, that they had to click on Send Funds -> Personal tab -> other. This way fees drop down to zero most of the times for them.
I can safely say that this current situation is pretty confusing for most people. Especially since they have to read new rules outside of BitMarket.eu site which is by design wrong. And since Paypal is my only option and I am a miner mainly (thus selling mostly), I have taken a pretty big beating in my income out of the blue.
Obligatory informative popups with instructions how buyers can pay least possible fees like: "Send Funds -> Personal tab -> other" are the best and fairest way. A link to this Paypal Fees calculator could come in handy too http://goo.gl/C9nwk.
I strongly believe you should consider this idea.
I really like BitMarket.eu and I prefer it for many reasons. And I bet you know too, that since every other exchange ditched it and most people have an account of it directrly connected to a bank account and ready to fire, Paypal is your strong niche card. It doesn't make sense to hinder it's exchange this way.