If you are on city water they can probably tell you what pressure they run in the pipes.
Will it be enough? Municipal water supply and well system pressures will be lower than the rating for the RO unit. The RO unit will give you water regardless. They work better at higher pressures though. Is it worth a booster pump? I guess that depends on several factors. If the unit takes forever to produce enough RO water, higher pressure will improve the flow through the membrane. If you pay an arm and a leg for water you will waste less since the rejection ratio is better with the higher pressure. But then you are also running an electric pump... Most people forgo the booster pump and get a unit that is rated to put out much more water than they need. Knowing that their pressure is lower and their water temperature is colder so not to expect the same output as the unit is rated at. It is not uncommon to see half the rated output when running a unit on home water pressure and temperature without a booster pump. RO units are so cheap though that you can easily get a larger capacity unit for a small increase in price and deal with the fact that it isn't producing at it's max capacity and still have plenty of RO water in the end.
If all else fails you could if needed add a booster pump later.