Visited 15.09.23
It is only 6 euros to access the Cairn de Petit Mont. Given the size of the site that is good value. It includes a group tour in French of the Cairn & Dolmen 3b, which is off limits without a tour guide. I requested some English commentary and the guide was obliging enough to give me a short lecture in English. I was also able to take photos in Chamber 3b.