ok, tell me how i could have played this better... (BAHH)

Would a bigger bet also have been appropriate? There's 800 in the pot. 1000 as a value bet is enough to recover if you fold to wiz or tinman push but doesn't give them the pot odds to call if they haven't flopped the straight or a straight and flush draw, isn't it? Or would that only be appropriate if there were only one other in the hand?

Wow! Is this an imposter Fell post? This bet is not decent. It's worse than terrible. Betting half the pot here is ridiculous. If you've given up on the kings, check it and get out. So far, you've had a limper and the small blind call a 5x raise preflop from the button. They both checked to the OP. If the OP thinks there's a trap out there, then he should check. Otherwise, he should be strong to make them pay the wrong price for their draw. At least bet the pot!

You may be right. That's why the 450 bet was so bad.

See my other post as to why I disagree with a pot-sized bet. Checking would not be terrible either, with the option to jam on an innocent turn card.