Anytime is a bad time to to bet for the place with the TAB. The odds for the place are often 25% or even less than the win odds with no real way of knowing the odds your taking until after the jump.
If a selection finishes unplaced on a 1Wx2P bet, the place outlay is money down the drain that could have been used for two win bets. If the selection places it's a poor value return and if it places with a winning run [as often happens], it's an extremely poor return on outlay.

Specialized place betting and looking for value on Betfair would be the way to go if regularly betting for the place I think. However, considering your stated profit margin so far scottsbluff, I'd be ignoring the place bets and loading up on the win bets for sure.