#1. The price depends on the leather (normal leather is approx 8-10k, exotic around 50k), style (retourne vs. sellier), hardware. You can find current prices updated here:
http://forum.purseblog.com/hermes-s...-travel-bag-prices-no-chatting-722677-16.html
#2. Due to limited amount of bags against demand, they are commonly not available to walk in customers. You have to be put on a waitlist, and/or become a frequent customer/VIP of the store.
#3. The wait depends, from a few months to 2 years even.
#4. When you get "the call" from the store, you come in, check it out. If you decide to pick it up then you pay for it. There's no deposit.
#5. Depending on the leather, some are more durable than the others to the elements (eg. some leather will blister in the rain), but H bag will last beautifully for decades if taken care of. Check out the reference section of the forum. Once in a while if need be you can send your bag on a spa (cost a few hundreds).
EDIT: there are lots and lots of information on this forum so keep reading. Good luck on finding your dream bag!