Whatever you pay for a system you must win that back before you make any profit, same with paying for tips.

Anyone can make up a list of winners showing big profits, so if you can't get a cast-iron and written money back guarantee [by the person selling it, not just a business name] of the system's profitability over say 6 mths., don't buy it.

If the address is a PO box, don't buy it.
If the phone no. is a mobile, don't buy it.
If the seller has no name that can be traced to an address, don't buy it.
If the seller will only accept, cash, money order or bank check, don't buy it.
If the seller is in QLD, don't buy it.
Finally, if it sounds too good to be true ....it is :-)