I'm trying to figure out a way to make a raised feeder/food storage bin out of one of those clear totes...
You can get a regular pre-made one of these that won't leak for only $20 at KVvet
(click here) ... A tupperware bin that size is gonna run you $10-15 and then you have to buy the bowls, so you really won't save any money, but you have to go through the hassle and then worry about it being waterproof. So if you want one of these I would suggest buying it from KV..
That being said, the thing I don't like about store-n-feed things is that they don't hold enough. You'll be hard pressed to find one to hold 30lbs, and since you will be buying 30lb bags of dog food, you will have to get another holder to store the extra that doesn't fit in the feeder.
At our house we use a wooden raised feeder, and we bought a pretty umbra trash can with a lid (so it is airtight) that has always held just zoey's food.