When looking for an affordable and reasonably accurate device to measure the (standby) power consumption of old power supplies, I came across the ELV EA 8000 Energy Analyzer. It’s being sold as complete device or as a kit; I went for the kit to spend some time with it and have a better look inside.
It has two power measuring ranges (40 and 3680 VA), several measuring functions (e.g., active / reactive / complex power, power factor, costs), storage space for 10 devices and up to three different electricity tariffs. Before buying, I was already aware that it has some flaws, but more about that after the assembly.