@DHAnderson the vMX runs as a virtual appliance within Azure, so it uses a standard Azure compute instance, most likely a 'Standard_F4s_V2' (but could be a 'Standard_D2_v2' or 'Standard_D2_v3' too). This means you are paying for Azure compute charges just as you would for any other server in Azure. You can use the Azure pricing calculator here, https://azure.microsoft.com/en-au/pricing/calculator/, to determine a rough idea of what it will cost for the compute platform, it various between country and region. You can also use the calculator to estimate data transfer costs. Whether you use an ExpressRoute or an AutoVPN to a Meraki vMX really comes down to the expected transfer of data out of Azure - it costs less when using ExpressRoute. When you start transferring more than about 1TB to 1.5TB per month out of Azure then you need to consider ExpressRoute (that's assuming the vMX can do the bandwidth you want). That's based on my calculations, but I'd advise doing them yourself for your region.
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