I am thinking of buying a hardware wallet too and Ledger wallet seems to be the cheapest ones around, btw what's the difference between the different ledger wallets?
Ledger HW.1 is a good way to get a low cost introduction to bitcoin hardware wallets. Once you find you like the security consider moving up to a Trezor. The advanced features will make you wonder why you did not buy one in the first place.
Trezor is good but way too costly but I guess if you have tonnes of bitcoin it makes sense investing in it.
Well that is the point. Folks with more than a couple of bitcoin to protect tend to either use Armory for cold storage using two separate computers or Trezor. Both have been around for a few years and are well proven. Trezor is made by the same team who created the first bitcoin mining pool.