christopherstamper

for the record, this did the trick (top of form-checkout.php)

//	If the user is not authorized, they cannot checkout
if ((get_user_meta(get_current_user_id(), 'mepr_authorized', 1))!= TRUE)
{
	echo apply_filters( 'woocommerce_checkout_must_be_logged_in_message', __( 'You must be authorized in order to checkout! Please make sure you have uploaded the required logo file, and then give us 3-6 days to process the request and authorize your account.', 'woocommerce' ) );
	return;
}