Can I have 30 75-watt lights in a 15-amp circuit breaker and 230 volts?
Strictly speaking, you are correct. The circuit can handle 15 A * 230 V = 3450 W before tripping*. As a safety margin, you want to stay below 80% of that, or 2760 W. Your 30 bulbs, at 75 W per bulb, draw 2250 W total, which is within the safe operating load of the circuit. So, from a physical standpoint, you're good. #14 wire is appropriate for a 15 A circuit.

However, as mentioned, you want to be aware of any local codes which limit the number of fixtures or receptacles on the circuit. As @isherwood mentions, too, you may want to consider a lower-power bulb (like LED or CFL) if it works in your situation, or an alternative lighting solution - e.g., do you really need 30 bulbs? Could you get the same result using half as many bulbs that output more light? 2200 W is a lot of power usage for lighting, so any way you can reduce that will be beneficial to your wallet :)



*In a perfect world. In the real world, breakers don't trip immediately when reaching their current limit, etc, etc.