Depends on the game, but assuming for now that you're playing 5-card
draw straight high poker (your typical home game) with no wild cards,
it's about a 12-to-1 shot (actually 4 in 47). Of course, you also
have to add to that the odds of a mere straight winning the hand, and
the expected gain of the bets you have to make to stay in based on
pot size, so it's always a bad bet in that game, unless some really
bizarre circumstances happen: for example, if you also have the chance
for a flush (i.e. your straight draw is also suited), or you're in the
last position in a dealer-ante or blind-and-straddle game so your
first round is free and no one raised. Even then it's not worth
betting a straight, but a cheap call might be OK.