I see your numbers with the A100. However, consider the 3090 which is down to $1000 and uses 350W. Double that if you consider cooling and overhead in a data center. In Europe the electricity prices are through the roof and easily cost >0.5$/kWh. If you use those numbers a single card would cost you 0.35kW * 2 * 0.5$/kWh * 24h * 365 = 3066$ per year. So I guess it highly depends on your specific location and circumstances.