Most of the pocket (pico) projectors in that price range may only be a hundred lumens at best, a good daylight projector should be in the couple thousand lumens.
A 100-lumen projector should only be used in a fairly dim to dark room, and at 4 feet you may get less than a 3-foot diagonal. Also, a text-heavy presentation will most likely need a higher resolution then some of the cheapies will be capable of.
You'd be better off to search google for "best portable project" rather than asking here, and god forbid don't look at the 10 billion auctions that are not in your country.
I can help you with conflicting terminology if needed but the last conference room projector I installed was over 3 years ago and much may have changed since then.
edit; don't forget to look for all the needed inputs of what you plan on driving the projector with.
