read the APrk post pengo

the layer or bookie set the odds if you wish on the blue side
OR
the backer can ask for odds >> the pink side.

as a layer you either do 1 of 2 things
1. set your own price on the blue side like the bloke did in APrk (he is letting someone on @ $8.40 << his own odds....his own decision...jhe is the bookie / layer
or
2. let someone on at the odds they are asking for (the pink side) this side is the backer asking for those odds. its a matter of whether the layer / bookie wants to say yes.
this is why the pink side is always more in price. Thats the side of the hungry backer who wants better odds
the blue side is where the stingy bookie / layert sits only wanting to give sml odds

who sets the odds ? >>>> either can. thats the luxury of it all.