DS was Indiana Jones for 2 Halloween's (inc. one at WDW!). Here are some tips:
1. The Whip - the ones at the Indiana Jones Outpost are expensive ($60, real leather and could hurt someone). Go to the local costume shop and you can find a fake leather whip that looks pretty realistic for $10 or under. We found one at our local costume shop for that price.
2. The Shirt -- boil a big pot of water (like a pot you'd cook a load of pasta in), take it off the heat, add a bunch of tea bags and let them steep. Find a white cotton button down type shirt, put it into the steeped tea for about 10-20 mins. It will turn it a lovely shade of brown and will look v. much like Indy's shirt. You can either buy a new white shirt at the store (v. inexpensive at Wal-Mart, even cheaper at Salvation Army). Or you can sacrifice one you already have.
3. The Hat - Indiana Jones Outpost has the Indiana Jones hat. I think the kids version was $35 and the adult version far more (again, maybe $50-60). We bought DS the "official" one long before he wanted to be Indy for Halloween, so we were set w/that.
4. The Belt -- we just used DS's belt. It was pretty beat on. We tied a small leather pouch (from some dice game) to it. He also had a holster and toy gun (but just the holster at WDW).
5. The Jacket - we found a cheap "flight jacket" that was fake leather and v. inexpensive at Burlington Coat Factory. However, it was too warm in WDW to wear it, so DS used a fishing vest that he happened to have. It worked and looked cute b/c it had loads of pockets. It was perfect to wear at home b/c Halloween night was chilly enough for the jacket.
I hope this helps you out some. Good luck ... DS loved his costume and looked great in it!!!!
Br'er Briere -- I notice you're from Hamburg! Go to George's Costume Shop in the Eastern Hills Mall. That's where I got DS's whip!!!! They may also have a costume fedora. We found the fishing vest at Gander Mountain and it was pretty inexpensive as well.