There may have others offering similar tours, which is most probably cheaper because it’s 2 days less, that will also mean it demands real stamina to complete within the shorter days, more intensive or challenging for sure. It’s not how fast you should ride, but the experiences, feel and beautiful scenery all the way… the key is always to enjoy and complete it.
SCT have really thought through the whole experience of the trip well, so kudos to the planning and execution! ??