Merlin has new 7000 series 105 for $438 so rule out the used 5800 for $450. I don't think I would pay $100 more for Sora over Claris. Neither group can be upgraded piecemeal in the future, same with Tiagra. Whatever you decide on, double check that the shifters come with all cables, not an insignificant cost if you have to buy them separately.