better by the gallon??

[Spidermom]

I'm eager to widen my scope of wine tasting.
In time, with guidence from this board, I will! However, I'm currently a "White Zinfandel" gal, and I know that this particular type is poo-pooed by "those in the know". My husband recently came across three brands that come in "boxes" (5 liters total)...they are "Almaden", "Peter Vella" and "Franzia". Is buying this much wine a good "deal" or a waste of money. My other concern is are they any good? Thanks for your help!