In reply to Juanito London:
Hi,
I did Orizaba in March this year without a guide but the bloke that drove us from Tlachichuca to Piedra Grande (Carlos) was a guide. He also went up on the same day with us and was the first to summit the mountain with ease.
+52 245 106 3639 - This number belongs to Carlos's dad, they run a mountaineering company from Tlachichuca. You can Whatsapp him and find out about prices and other info.
I made a video of my trip where you can see Carlos answering some questions, feel free to check it out: