can anyone tell me how to pay for purchased items
If you're talking about purchasing from a storefront what I recommend is checking various economic calculators like this one (http://nseconomy.thirdgeek.com) to make sure you have enough money earmarked. If it's military, make sure your're not spending your entire defence budget on one branch of the military (I'd use no more than about 25 percent of your overall defence budget as a general guide to what you could conceiveably afford to buy).
Once you've figured out if you have enough money, it's usually enough just to type something like, "money wired on confirmation," and the money's presumed wired if your order is confirmed.
Hope this helps!