[Suicide Junkie]

Just keep the trades small, and don't trade with anyone who's ripped you off in the past.

The less you swap in any one trade, the less you stand to lose.
Breaking up a trade over a couple turns means you only risk a fraction of the trade's value it each step and can back out at any time.


Of course, if you're not quite so paranoid about your neighbours, you'll be a little more easygoing.

Note:
If you meet a race called the "Hedgemony of Evil", paranoia is probably justified.