how to buy online with out using a service like paypal.com and alertpay?

Any site that uses Paypal can accept a credit card payment: the Paypal model allows you to enter card details instead of an account name when you're sent to the site for payment. A huge number of sites also accept credit cards without the Paypal middleman. In the UK, you're more likely to find companies taking card payments than you are to find those accepting Paypal.

Direct bank transfer is unlikely, although credit cards are commonly accepted as a payment method. Amazon accept credit cards for example.

I use a credit card online all the time. The great advantage is that you can charge back if the deal is not honest, though I have never had to do that. I also use payment processors like PayPal and that also works well. You can only choose one of the payment options given by the web site. If they don't accept credit cards you can't make them .

most sites allow you to pay directly from your bank. although i wouldnt always advise this for sercurity reasons, but there should be a option on the site itself with the option. it might take a little looking around. some sites also let you pay from your mobile (they charge with texts)