A more general opinion on these characters is found in this previous post.
Dave Hester – He’s become my favorite character. He seems to be the most knowledgeable and the best at the bidding process. He doesn’t bid until the end to see how serious the other bidders are. If a guy started the bid at 100 and it’s up to 1,000 and he’s still bidding, Dave has an idea what he’s dealing with and he haven’t given away any of his own bidding agenda. His attitude is also professional and he has an eye for spotting valuable merchandise. Easily the smartest character on the show and shows it episode after episode with big profits. A good example was when he was bidding on the boxes from China. There were about a 100 boxes in there and he figured to ship that amount of goods cost 4-5 thousand bucks. No one is spending that much money to ship unless there is merchandise worth value. He spent 9k for the locker and it turned out to be 20k of profit. I especially liked how he shot down Mark in the bidding process. Mark is used to upping it 100 bucks or so but when Dave started boosting it a grand at a time, he backed down quickly. He almost makes the show unfair as only Barry really has a shot against him and that’s just by getting lucky.
Jarrod and Brandi – Dumb luck is the key to their success. They just seem to get lucky with certain purchases. I’ve already wrote that they benefit the most from being on the show so it doesn’t really matter how successful they are bidding on lockers. Brandi will probably be offered to do a porno for tens of thousands of dollars which would be easy money and publicity. They are good for the show though because they bring some personality.
Barry – He’s obviously worth millions of dollars. He has new cars on every episode and doesn’t really care about selling the small goods. He’s looking for antiques and collectables that are worth thousands of dollars. This causes him to bid on a lot of mystery. He’ll see a hole in the wall or a locked trunk and start bidding up the locker because of the possibility of something good. He’s good for the show because he is willing to spend money if he starts getting curious.
Darrell – Easily the worst character. He seems to have decent knowledge but he’s too much of a cheapskate and doesn’t have any balls. His personality is that of a big, dumb oaf. I have a hard time taking him seriously with that weird tan.