Some alternates to SAS – these are all listed in the guide book.
mid-priced – “proficiently run”
http://andeanlife.com/incatrail.htm
mid-priced – “small but highly professional”
http://perutreks.com/inca_trail_04d_prices.html
mid-priced – “upmarket”
http://qente.com/ingles/inca_trail/trad_cain_4d_3n.html
mid-priced – “have long been popular for inexpensive tours, but they’ve recently hiked their rates up to $350; they are still worth checking out though.
http://unitedmice.com/en/tour04.html
upscale
http://www.inkanatura.com/machu_picchu_incatrail_classic.asp
upscale – this one is “frequently recommended” but pricey.
http://www.andeantreks.com/Admin/Trips/itineraries/inca_trail_to_machu_picchu.htm