If you are going to hang onto that deck for a long time, and you have the money, the right bag is pretty luxurious, no doubt.
But if you are on a budget, don't underestimate places like Goodwill and Walmart. I've picked up backpacks there for about $20, it was intended for a student with a ton of books and a laptop, which means lots of cubby holes for connectors and batteries. I've seen 2 other tapers with the exact same backpack too. I've seen people use fishing tackle bags, soft coolers, gym bags, whatever.
Don't forget the most important thing, though... a beer guard! If you have a Portabrace or SonicCase, the soft plastic covers work great. I you don't have a bag with a plastic window, bring an old towel or tshirt to drape over the bag, that will absorb/deflect most of it.