I rarely buy anything at the after-races sales with a view to racing it, tbh. Generally all I'm looking for is something that has won at least 5 group 1s and is a decent breeding prospect. It really depends what you're after, though? If you're looking for something to race I would suggest not just looking at the handicap rating, go into the horse screen and look through its past runs. Has it been run over distances it doesn't like, indicating that it may improve over its pref distance? Has it run good times when it has won? What level is it racing at? You can pick up some decent horses from selling/claiming races, however they tend to be older and well past their prime, but these ones may be absolute bargains to add to your breeding program. I once bought an old mare who won a selling race (she was 9 I think) who had won 12 group 1 races in her younger years. I retired her to stud and she's produced some absolute crackers for me.
If you're looking to start out and want to get some truly talented horses to kick off your stable, buy the cheapest mares you can, as many as possible, retire them to breed and use the most expensive game stallion you can find. If you don't have enough money to use the best game horses just go back to the sales and buy the cheapest stallion you can. Breed him to all your mares and in a couple of seasons when the foals turn two send them all to the sales (without racing them - they're probably donkeys and running them will give them a handicap rating, probably a low one, bringing down their price a LOT). Afterwards, depending on how many you managed to produce and sell, you should have well over a million and can now start using decent game stallions on your el cheapo mares. The things is, even when using truly slow mares you can still breed some decent horses, so keep the foals by that good game stallion and run them yourself- hopefully there will be a couple of good ones that will win you plenty of money. Within a few years you should have enough money to start buying the best group winning horses at the sales (if you manage to catch them there - there aren't many), retire them to stud and voila! You should be winning loads of group 1s in no time.
And if none of that was what you were looking for, then just... ignore it.
I ramble when I start talking about SO. It's a disease.
