How valuable are runner-runner low draws in O8b - are they worth chasing for one bet on the flop?

Lets say I've got A2, and the flop is 49T. Is it worth calling a bet on the flop to chase your nut low?

That hand Never, unless it was 10 way capped action preflop. You are chasing a less than 20% chance of hitting for half the pot or 10 to 1. Not to mention the times you are quartered.

If you are getting 12 to 1, with 3 or 4 opponents, on your flop call (say .50 with a $6 pot) you have to remember that if a low comes you still have nothing! you have to call a double bet getting say 9 to 1 (another $1 in a $9 pot) on the turn. your true pot odds are something in the neighborhood $1.50 to win $6 that isn't 10 to 1 in my book.

now, add in the times you are quartered and the times there are raises on the turn and I would say your pot odds are in the 3 to 1 area on a 10 to 1 shot. Add in 4 more opponents and its still a pretty clear cut fold

A23 on a 4T9 board is a fold in that scenario. Suckers chase runner runner lows. Now if you had A239 with runner runner flush draw then you may want to see another card since you may be playing for the whole pot if the right turn card comes up (a 5 gives you a good straight draw, you could pick up a flush draw, an A, 2, or 3 gives you not only a low draw but 2 pair). and you can't be counterfeited on your low draw giving you 21 outs on the river instead of the 16 for a bare A2 .

read my post above.

I can't think of any reasonable scenario where calling with only a bare A2 would be correct or even an A2 with runner runner flush or A2 with middle pair. toeven considr calling to runner low you need a backup low along with some longshot high possibility, and thats just to consider calling with it