20$ Rebuy, failed bluff in late stage - reasonable play or suicide?

[comfortably_numb]

Like previous posters wrote, I'd also prefer a reraise to 7.5k or 8k pre-flop and flop is a raise too, to find out a bit more where you probably stand.
Not done that way, on Turn I'd call again and the same on River. I assume he will not bet more on river if river is blank to that board.
In this situation I would play that way to gain information cheaply (and you get great pot odds).
It must not be the right play, but I would like to know with which cards he played that strange and I record that for further action.
In some rare cases you might get shown AQo ...
Nevertheless, villain played the hand quite bad, imo.