You can try to hide in something like Gold, but
it won't do you a bit of good. The government is not that dumb. They already have in the law provisions requiring reporting of transactions over $600. They'll go to a fully-electronic currency (we're damn close to being there now)
and force clearing of all transactions through The Fed. This will effectively create a 100% reportable - and taxable - data stream.
If you try to barter around it, and you will, they'll fix that too. Treasury will simply expand the
already existing IRS program for "rats." Your neighbor and everyone else will be "enticed" with a 20% reward for all "off-grid" transactions that they report. And civil forfeiture will be used to literally steal everything you own when - not if - you get caught.