Implement PayPal Micropayments in WebApp

Closed - This job posting has been filled and work has been completed.

Job Description

I need to seamlessly implement micro-payment option within my web app.

Some use cases/requirements include:

user has 3 purchase options (and receives a number of coins per options) which should be handled via paypal-micropayments

user can "gift" a number of coins to another user

deduct coins once used or gifted

apply offer code for discount

keep track of user payments for pro-rating tier movement (i.e. if middle option = $10 and low = $2; then i want to charge user only $8 to move from low to middle (so must keep track)) etc.

it would also be awesome to have a simple admin panel (i.e. to set offer code that handles calculation, set number of coins purchased/gifted, etc.). I imagine this would be done with javascript?