Why wouldn't you feel safe? This is nothing like an investment, it is an entirely different economy. If you know all of the items, habits, prices etc. You'll be able to vastly increase the money in your inventory. It isn't like these items are going to all suddenly become valueless, if you trade your way up, it is a great idea to put some money into the market.

I think it wise to invest a bit of money. I have a few premium alts and have gotten my more than i put in and the entertainment. and with the new premium tool item it should be even easier. its totally up to you though.

TF2 as mentioned above is a completely different box of hats. (See what I did there?)
Prices are considerably more stable, and speaking as an avid follower of stock markets, profits are much more reliable. I invested the absolute minimum into my account, buying a Backburner from the store, and have increased that 50c investment to over $100 value.

TF2 profit is proportional, the more capital you have to begin with, the larger your return on investment.

I've never put a penny into the game, except for buying it for $10 -- my BP was made entirely from trading those drops up and up and up.

IMO, it isn't a bad idea to put ~$300 into your account, if you've just started out, and wish to skip the first bit of your trading career.
The first week(s), if you don't spend anything, (or spent very little) will just be used to get to an amount that you could gain in a week if you put ~$100 into it.

Originally posted by samhudson333:

I move thousands of dollars a week in and out of TF2. I can't recomend it enough. At this point in our lives most of us don't have the money to invest and profit from the stock market. This is the next best thing. In a few days I'll have made enough profit to buy this watch:

http://www.omegawatches.com/gents/seamaster/300-m-diver-chronometer/22208000

ohmygosh, I used to have this watch!
You'll be very happy with it c: