ehh...it all depends, based on your bike, you can probably fit a 48T crank upfront without going to a road oriented bike. I've seen them as cheap as 150 on ebay and various other places. a new cassette. my friend paid 40 for his SRAM 12-25 cassette. A new chain will be needed, 35 bucks maybe, add 5 get a power link from SRAM, so say 40...so 230 bucks? roughly? give or take, there are MANY factors that can go into this. So 230 is the middle of the road I'm sure used would be much cheaper, and you might actually be able to just change the top chainring on your current crankset. As far as speed goes, the rear cassette allows you to have a tighter cluster, but will not actually give you a better/higher ratio for speed.