(a) An agreement described by Section 442.154 may authorize the foundation to, at the site that is the subject of the agreement:
(1) charge and collect fees in connection with the foundation's activities at the site, including fees for viewing special exhibits or films, attending programs or events, and using the facilities at the site; and
(2) collect revenue from gift shop and concession sales at the site.
(b) The foundation shall hold, invest, manage, use, and apply money received from the fees and sales described by Subsection (a) only for the benefit of the sites described by Section 442.152(a).