Is purchase tax due on a property bought at auction in Israel?

Yes. Purchase tax (mas rechisha) applies to auction purchases in the same way as to conventional purchases. As a non-resident foreign buyer, you pay the foreign buyer rate — currently starting at 8% — regardless of how the property was sold. The only way to receive a reduced rate is if you qualify as an Oleh Chadash (new immigrant) or meet another specific exemption category under Israeli tax law.