Beardies need at least a 40 gallon tank, and Leopard geckos can live happily in a ten gallon (but really, a 20 Long isn't much more enxpensive and it gives them sooo much more space!)

Leos are MUCH cheaper to set up than beardies, they also live a lot longer, but they're both wonderful pets. My beardie boy is on my lap right now.