Hello, @DaveK !
How do I compare the retail prices REST API and the portal prices?
Usually confusion regarding difference in prices when comparing one place with another is a variable that affects the price such as the OS license or forgetting to update the location. This is easy to overlook, especially when default values might not be what you were expecting.
Below I've used your request in Postman which returned the same 0.2988
GBP that you are seeing. I then compared this to the Azure Pricing Calculator which quoted £0.299 as long as I selected an operating system with no additional cost. Looking at the Azure Portal, we see the same price after a bit of math ($252.58/month or $0.346/hour which converts to £0.2988/hour at the conversion rate listed of 0.8636).
Let me know if you are seeing something different and I'd be happy to investigate this further. I hope this helps!
Total for an E4ds v5 VM using the Azure Portal: $252.58/month ($0.346/hour or £0.2988/hour with 730 hours at the conversion rate listed of 0.8636)
Total for an E4ds v5 VM using the REST API: £0.2988
https://prices.azure.com/api/retail/prices?currencyCode='GBP'&$filter=productName eq 'Virtual Machines Edsv5 Series' and skuName eq 'E4ds v5' and armRegionName eq 'westeurope' and priceType eq 'Consumption'
Total for an E4ds v5 VM using the Azure Pricing Calculator: £0.299