Title insurance for sheriff sale property/foreclosure?

I'm interested in potentially purchasing a property at a sheriff sale- I'm trying to take care of due diligence and get an abbreviated title report (the full report is $500, but evidently a 'lot book' report, which includes any liens, is $150)- At what point are you able to actually get title insurance on the property? It seems if you buy the property and then wait to be issued a sheriff's deed before getting title insurance that there is a period of vulnerability-