I have a smart plug with power consumption monitoring at home - it's a practical thing, I use it constantly to keep tabs on my appliances, and it fits the budget. But for a friend, it would make sense to clarify which platform he prefers: if it's Home Assistant, Google Home, or Apple HomeKit, there will be more options. In the 5000-ruble range, there's a solid selection - smart plugs with energy monitoring (they're compatible with pretty much everything), motion and humidity sensors for automation, or a good smart hub if he doesn't have one yet. The last option is especially useful: it expands the system's capabilities and lets you connect more devices at once. The specific product depends on what he already has installed and what his plans are for the next steps.