I'm thinking of replacing the drivetrain on my giant tcr c2 2007.
It has 39/53 crank and a 12-27 cassette. I'm looking to improve my climbing gears.

The options are to put on a 12-30 cassette. To do so will require a new derailleur(shimano 6700 med cage) The chain and cassette will need to be replaced soon anyway. Or replace the chainrings to a 36/52. I'm not sure if that's possible.

The shop said option 1 would be about us$250. Would I gain enough for the expense? They seamed reluctant to explore the second option.

I could buy a new bike but that may not go over well with the CFO