CP, when you say "massive", what are you referring to?

I did a quick comparison:
8 horse gallops, 1st favourite

2009: Average 1st Fave winner nett Betfair back price = $2.58

Actual strike rate as dollars = $2.82....-9%

2014: Average 1st Fave winner nett Betfair back price = $2.56

Actual strike rate as dollars = $2.72...-6%

* Data based on Aus & NZ races, min $5k in Betfair pool at jump.

The strike rate has changed (only a 1 year mean for each sample) but prices stayed the same?