I'm not sure the IRS has provided much guidance yet, but if your 1099 income ends up on a Schedule C (self-employed) it gets carried over to Schedule SE (self-employment taxes) and both halves of employment taxes are assessed.

I use Schedule C and treat it as a business, which definitely enables me to declare travel expenses incurred when I travel to coin shows and acquire inventory (I sell other types of coins).

The alternative is to declare it on the 1040 as miscellaneous (hobby) income, which becomes like jury duty pay, or Schedule D as capital gains (like sale of a home or stock), which avoids being carried to Schedule SE as self-employment income and thus bypasses FICA and other employment taxes. These methods MAY affect how you can deduct expenses, though - it has been a long time since I dealt with any of that and, again, I don't know if the IRS has provided recent direction.