I've had fantastic results with the Le Maitre Neutron XS Hazer. It's a good few hundred more than what your looking for 700ish-800ish usually. But it is a very simple hazer and it works fantastic. Fantastic output. It is extremely clean and hassle free. Doesn't create any fire alarm problems at my facility. It may be controlled through either DMX, remote, or automatically. You should contact your local fire department or a fire marshall and just ask them for advice.
Some hazers and fog machines will not set off fire alarms but that also depends on what type of system your venue has. It also depends on what type of fluid you are using in the machines. Honestly, either way, if you use haze or fog, I would still have the fire alarms put in test and have someone man the fire pit (where the alarm control panel is). It's the smart thing to do just incase they are set off and the fire dept comes and then your venue gets fined.
In terms of a cheap hazer... Chauvet HZ-1000 Hazer. It honestly is the only hazer that is under 500 but still is a good machine. If you really want to go to the next level, it's around 800-2,000.