There are several things that you need to take into account when you are looking for an outdoor theatre projector. Here is a quick checklist of requirements to keep in mind:
Brightness: 2,000 lumens or better
Resolution: HD (720p or 1080p)
Connectivity: HDMI
Audio: Internal Speakers
Several different projectors under $200 can be used for an outdoor theater, but the GooDee Video Projector 230" HD is probably the best option.