Dealer gave me wrong equal-I-zer size?

I kind of had the same issue. I have a 450 lb hitch weight dry and was given a Fastway E2 with the 500 lb rating on the hitch. I noted that once I loaded it up, I'd likely be over that and asked if I could get the next one up. They guy said he thought the one they supplied would work but OK. I asked how much and he said 10 bucks. I was like, OK...

I'm thinking it could be a similar situation to the Equalizer in that the main difference was only in the bars? Irrespective, I'm set up for the next trailer unless we go fiver.