Useful answers, with the maths visible

Cost by hour, night, month and year.

Energy use, temperature and installation ranges.

Official Sony and Microsoft wattages: hour, month and year.

Oil, convector or ceramic: hour, month and full winter.

Estimate by vehicle size, body condition and paint level.

Full charge, 100 km and yearly cost.

Fees, shipping, insurance and break-even value.

What the marketplace keeps and what you keep, from official fee tables.

Black Friday & sales: how much they actually take off.

What El Gordo returns on average, with the official prize table.