2013 may be on close outs as that is last year, so numbers available may be spotty ..
don't understand all the technical stuff about gears.
maybe an internal gear bike would be good enough.. there, for example are 8 speeds all of them different,
each from first, easiest gear, next, larger than the last.. in sequence, so not confusing.
they are quite improved in the last 2 score and five years..
what is your current cycling ambition?
derailleur gears are somewhat confusing , because they overlap in the range of gear ratios
so though the count of gears on the wheel and the crank may total 24, for example
many are redundant and as i say, overlapping when you do the ratio math.