HST is a third-rail the Tories don't want to grab again, it was implemented in Saskatchewan in 1991 under Grant Devine and was revoked about 6 months later by Roy Romanow (NDP).  Made for a lot of hate and misery for business owners switching accounting systems twice in a year, but I don't believe Saskatchewan had a gift from the Feds to switch that had to paid back like BC.  BTW, it had a lot of opposition at the time because it applied to children's clothing and restaurant meals.