So I am sitting in my hotel room in PVG and looking up fares for an upcoming vacation. I was looking at fares for HKG-BKK and PVG-HKG and I was using Farecompare, ITA and Cathay's web site. I noticed a huge difference by going to Cathay's site, some of the fares are almost half the price of the other two sites. I looked at coach and biz class, same flt numbers and dates. Is this normal? Could it be because my IP address is PVG? Problem with Cathay's web site?

Possibly different fare buckets, which are accessible via Cathay's site but not the GDS. E.g. I regularly turn up W fares on aa.com which can't be found on EF.

Cathay has great holiday packages at really reasonable prices. Check PVG- HK leg with Dragon Air as well.