Apple Watch Series 3 vs Series 4: What’s the difference?

Discounts and offers aside though, let’s get it out of the way: the Series 4 is expensive. The smaller, 40mm model has an RRP of $399 (399/AU$599), or $499 (499/AU$699) if you want cellular connectivity. Want a bigger size? That’ll cost you extra: $429 (429/AU$649) for the 44mm GPS model, or $529 (529/AU$799) for the LTE version.