There are bullets and bullets. A 35mm flakpanzer round is very much not the same cost as a 9mm bullet from a random handgun.

Similarly, there are lasers and lasers. A 30kW laser like being tested in 2015 is nowhere near the 300 kW monsters like HELCAP meant for missile defence.

To compare, 300kW laser delivers 300.000 joules on target every second. Now, granted, that “target” might be a circle bigger than your actual target, but then, bullets can also miss. A 20mm solid bullet from a Phalanx CIWS delivers some 60.000 joules on target per hit.