trading with $100000 in demo mode certainly doesn't work.
there are a lot of sentimental and emotional trades we make with such a high margin and we tend to hold our positions even when they are at loss.
anyone who gives you as low as $250 to trade in demo is a real place where you can learn as if you are trading for real.
if you want to trade with $250, $500, $2500 and up to $50000 in demo mode, my advise is, you visit
http://forexfortune.in/demo.asp and select an amount which you are planning to invest so that you can judge how successful you are in trading.
good luck.