It depends on who is going to the beta test session. If it's just close friends hanging out at a game store, you probably don't need to. If you're working with perfect strangers, getting some hot dogs and soda or something probably isn't a bad idea. I guess a lot of it depends on how much playing you plan to do. Are you just demoing/working through a few games with decks or is it a longer affair (building decks)?
I haven't decided yet. One of the fundamental issues of the game is that it's not really intended to be a
collectible card game - there aren't really uncommons or rares and there'd be little impetus to trade. Still it's a game of varied effects and potentially certain decks will be more passive than others, some more 'aggressive' (there are exactly zero creatures), etc etc...
One of my primary concerns is whether or not I'm dealing with the number values correctly. It's not high math by any means, I just need to determine a better scale of how much certain effects should cost, if my primary system for attaining gold('mana') is correctly executed, blah blah. I think I'm going to start with my mother's Mensa friends before I take it to a more random community and I already know how to entertain them, it's the strangers I'm more concerned with.
I tried a few Google searches in the vein of "how do I beta test/playtest" but nothing really came up beyond software beta testing. If anyone has any Internet resources describing or outlining either their own experience or someone else's I'd be most appreciative.