Gears, cranksets, and mountains....help!

[Starfish]

A mountain cassette and derailleur is obviously the cheapest way to go, but you lose so many of the in-between gears that you're almost always pedaling at a cadence that isn't ideal for you.

Well, I put an 11-32 on last year, and while I did notice some of the in-between gears disappear, I feel I have plenty of cadence choices. The resulting low gears really, really helped me do the climbing training I needed to climb 10,000 feet in one day for my event.

If I was riding across the country and doing serious mountain climbing, 4K, 5K, 6K feet for one pass, let alone a full day of climbing or multple passes, I would want those granny gears. That is where I am in my fitness and weight for all day climbing.

That is why I think it is so important to know the OP's background of training, fitness, strength, etc.