Based of the total $ 21 millions bitcoins that can be mined, it seems from the existing data
https://blockchain.info/charts/total-bitcoins just about $ 16 millions already in mined. There are still $5 millions left. We can not predict how long this remainder will be spent to mining. but obviously supply bitcoins will still continue despite reaching the limit.
I think it's the supply of bitcoin, not the dollar. Also bitcoin can be transfer with some sort of a hard drive wallet which you can transfer from your bitcoin wallet to that wallet which is more secure because you can take it were ever you want like a usb.