Budapest, Hungary SIM cards

[HappyCamp]

I will be going to Budapest, Hungary in a few days and I will be there for two weeks. Interested in buying two prepaid SIM cards with voice and data. Want to be able to call each other and hopefully have at least 500MB of data (more is better).

I will be checking out what look like are the big three:
Telenor
T-Mobile
Vodafone http://www.vodafone.hu/eng/1gb (maybe promising)

Initial looking it seems kind of expensive for data (though Vodafone looks interesting). But I might be looking at the wrong plans.

But not sure if there is an MVNO I should be looking at.

Thanks!