almost 100% of "respected posters" ( i assume you are referring to 2p2) do not respect 200nl 6m players' ranges, particularly ones with donkish stats.
if i hadnt seen this guy make a horribly out of line postflop bet before id pretty much say nice boat and fold without a lot of thought. donks are usually donks because they play too passively post flop, calling down with too much crap and not gettiing enough value/making their good hands transparent. when one of these players suddenly makes a weird bet like this you should thank him for being so bad; you just made a lot of money. BY FOLDING.