Getting a group dressed, eqipped, and active takes TIME, money, and effort. Armorers in particular are notoriously slow to fill orders. Some recruits may get frustrated waiting several months for equipment, others may simply lose interest and drift away. As the group becomes more self-sufficient you may be able to entice them back, but generally the people who are serious about being Roman will never quit. Very few of the people who contact you about joining your group will actually become active members.
Authenticity shows professionalism and dedication.
It is essential that everything we show to the general public be as accurate as we can reasonably make it. Do your best not only to maintain your historical accuracy, but to improve it. Many people have gone before you, wasting time and money on inaccurate gear, and have ended up replacing it. You can avoid repeating those mistakes by finding out where and how they got their better things. You won't regret it.