Fake +Rep?

allways check the profile attached to the rep and make sure its the same account your talking to.

I thought that scenario thinking that you have clicked the right links and checked that the empty account is the one with the +221 rep. But I saw that you new here so now I'm guessing what others guessing, which is that you clicked the link he sent you and then you didn't click the "Steam Profile" link from the ST page. So it most likely and impersonator as others said.

Then almost all of the steam users should be banned or something because almost everyone has an alt account.

You're wrong, there is nothing in ToS against multiple accounts ;) However, impersonation is againts ToS.
I recommend actually reading it since you agreed with it when registering on Steam. ;)
http://store.steampowered.com/subscriber_agreement/ <- Nothing about multiple accounts
http://store.steampowered.com/online_conduct/ <- Impersonation not allowed

When they feel they might get caught they just disappear, it's always good to delay the trade a bit, they always want things as fast as possible so they can leave without trace.