There are many 5442 variants/models.. And there is huge difference in price between models (even 2x)..
If we talk about models with zoom, normal line is coded as 5442E and models from that line are cheaper.
5442H variants are premium variants, in bigger chassis & much brighter (F/1.2 not F/1.8) zoom optics both from Ultra line (7xxx)...
All 5442 variants have the same 4Mpx 1/1.8" size sensor. Difference is in chassis, optics (constant vs zoom, how bright), light options (IR vs white) and generations (S3 means newest WizMind-S line with Video MetaData, AcuPick and 4th video stream).
Prices for Dahua Pro line in Europe are not cheap. Orbitaldigital shop gives 35% discount for all Spain Dahua catalog and for my knowledge this web shop have best prices in EU (without extra promotions/rabates).
If You look cheaper, go to Andy on this forum. Or his shop:
EmpireTech IPC-B5442E-ZE 1/1.8" CMOS 4MP WDR IR Bullet AI Network Came
Delivery to Europe takes usually 2 weeks and You don't pay any taxes/VAT..