Paypal Pay now button : Multiple fees description for single item
You can always add multiple items in a single form request. See this SO question: paying for multiple items (at once) via paypal...
amount of non-hosted paypal buy now buttin is not changing
_s_xclick is the secure (or saved) xclick command to which you submit an encrypted (or saved) button. But you cannot have plaintext fields in an encrypted button; you can only do that in a plain button (that's the point of encrypted buttons). You are mixing the two. Either encrypt the...