I have been trialing this with real $5 lay bets since only last Wednesday 6 Feb.

So far there have been 39 bets for 30 winning lays and 9 losing lays giving a return of $67.09 after commission of 6.5% (76.9% SR). TheSchmile's Gretchen was a lay pick today. ;) So far with my testing there have been 170 bets with 43 losing lays (74.7% SR).

I will place $200 aside for this and use the $5 level stakes method but I will use a percentage of bank rather than pure level stakes. This will be 2.5% of the $200 bank so starting at $5 lay bet. The bet amount will then increase if the bank increases and stay at that higher level should there be any loses (ratchet staking). This started today with 3 successful lay bets.

By the way, does anyone know of the strike rates per price in the $2 to $3 price range laying on betfair?

Just round figures:
I assume a $2 horse would win 50% of the time.
Would a $3 horse win 25% of the time?
What about a $2.50 horse? Would they split the difference and win 37.5% of the time (round figures)?

I'm just wondering.