If A is (utility of) status quo, B is winning option and C is its counterpart, then the default lottery (not playing) is A, and our 1000-rare lottery is (B+1000*C)/1001, so preferring to pass the lottery corresponds to 1000*(A-C)>(B-A). That is, no benefit B over A is more than 1000 times loss C below A.

Or, formulating as a bound on utility, even the small losses significant enough to think about them weight more than 1/1000th of the greatest possible prize. It looks like a reasonable enough heuristic for the choices of everyday life: don't get bogged down by seemingly small nuisances, they are actually bad enough to invest effort in systematically avoiding them.