Hi Benny,
Check out...
Oz Race Tools (Google search Aust.)

There you will find a quinella spread sheet set up , that calculates the different price combos once the prices have been inputted.

One can also input upper & lower parramiters to target.
It's very good.

With quinellas , one will find it amazing how close the final div pays just using the newspaper pre-post prices, inputted into the spredsheet.
This also applies to doubles, exactas & trifectas ...weird!

I was reading somewhere that races with exactly 9 runners is the best field size to target for quinellas. Value to risk.

I had some success at one stage inputting the newspaper prices into these 9 horse races setting the parramiters at $15-30

I hope this helps you out a little.
Cheers.

__________________
Cheers.