I don’t actually have an ecoommerce site but this section of the forum seems to fit the question better than any others.
I write content and aricles for clients. I have my own website. I want them to be able to pay for the service I have provided after I have written the articles, through a paypal page on my site. I have one problem. All my clients are different and the costings for each tends to be different. so I can not have a page which says Articles £20 and then the click button. It must somehow link to what the individual customer needs to pay.
Paypal is very confusing sometimes. Check out Dwolla. They only charge .25 cents per transaction. You can have your own hub page. You can prefill the money amounts in the hub page based on your needs. And it’s all pretty simple.
There is a feature in PayPal where you create a payment request for which sends an email for the requested amount to the recipient. The recipient then follows the link in the email which takes them to PayPal where they pay you for the requested amount in the same way as if they had clicked on a ‘Buy Now’ button on your website.