punter57,
As marcus said everyone to his own, but I think a lot is to do with your own circumstances, whether you bet everyday or once a week. If you are a once a week punter then I reckon keep going, if you are an everyday punter I can see no problem with stopping at a decent profit.
I had 1 bet today Ballina R1 Urgent Sea and got $6.9 place, that's a huge result for me, so why go any further, and risk losing what I had gained, I am in it for the $$$ and not the pleasure.
Just a matter of interest We see a lot of ideas on this forum and posters ask anyone with a data base to run it for them. The usual result is that the idea shows a loss, I JUST wonder on some the ideas whether if the data base people could run the particular method race to race across each state as they run whether the idea would show a DAILY PROFIT if one stopped when ahead.
Just food for thought.

Cheers