haven't tried it myself, but LME can be a bit more susceptible to being stale than DME (and since you're ordering online u don't know how old it is). Also that yeast isn't a true Bavarian Hef yeast but more of an american wheat.
for that price I think you could do better too. piece together the same set from a LHBS should net you at about $35 (ish) for DME and the same hop and a good Bavarian Hef yeast like White labs 300 or WYeast 3068 (unless you honestly prefer an american wheat above a true bavarian hef). + you can use plain ole table sugar lying around the house to carb them.