Jim,
YOU ARE CHARGING. Must be a chapter member to attend. Membership costs $10. SO YOU ARE CHARGING. Sort of like blackmail, want to attend a meeting or trade cards, pay us.
Look at this from another aspect. An important purpose of meetings is to sign new members. Yet your proposed policy denies admittance to those you hope to signup. Why would a prospective new collector want to join if they had to pay BEFORE they received information on the chapter and got to see how the chapter operates? Attendance of guests gives the chapter a chance to educate and recruit those people. Charging them $10 before admittance will discourage attendance and reduce your potential recruits. If you do not care about new recruits, persue your current policy and alienate them.
I will again point out that no other chapter charges anyone to attend their meeting or trade session. Memberships in those chapters is not required to attend as far as I know. Guests are welcome as they are potential members.
Paul