Hey Daisy,
I thought you were already on the way! This soudns a bit steep, 70 euros, almost $100!
there are several smaller shops in Mendoza that should get you a better deal, the most wellknown is Orviz:
Casa ORVIZ - Tienda de montaña de José Orviz
Juan B. Justo 532 Mendoza - CP 5500 - Argentina - TelFax: 54-261-4251281
info@orviz.com -
orviz@lanet.com.ar -
www.orviz.com Hope this helps,
Have a great trip, make lots of pix and most of all take care and be safe

H