So the word is that even with lots of cash you can't get most banks to talk to you if you want to run a bitcoin ATM business. However with some starting seed capital (cash and bitcoin) plus a local community of bitcoin users it seems that a 2-way ATM shouldn't require a bank account. If it were to dynamically modify its pricing based on the reserve levels of cash vs. coin and publish this info online then free market forces could help ensure it wouldn't run out of either type of money.
In other words people won't use it.
What? http://www.coindesk.com/robocoin-bitcoin-atm-cad1m-29-days/
If the offer is good enough the ATM will provide a chance for buyers or sellers who would ordinarily use localbitcoins to either buy or sell at the machine. It's the same mechanism that keeps the prices of the various exchanges relatively in line: arbitrage.
That is an interesting idea. Effectively, this ATM would become a method for localbitcoin traders to exchange with each other without directly meeting.
