Betchoice is a very good site to look at.
This is the one I would favour.
It has all the TABs & Betfair prices to compare with as well.
Plus market percentage at the bottom.

Dynamic odds is another , but this can cost money per month (approx $25) & has its own pre-post market which can be handy.

It also has a ,follow the money section, which could also be handy for those who like to following the so-called, smart money trail.

IAS are good , but have been known to do a few clever things in the past that may be seen as being designed to confuse the market, maybe to their benefit, seeing that they are bookmakers an all.
For example , putting up a set of prices where all the prices cant necessarily had by the punter.

Just a tip:
If one wishes to get a truer feel for the market using TAB prices on the Betchoice site...
Click onto the TAB that has the most money invested for that race,
By clicking onto that TABs header , it will display that TABs runners in price order.

You will be able to compare all the various prices for that runner at a glance.
It's a beautiful thing.

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Cheers.