Integrate PayPal API into VB.net website

This Job is best suited to an experienced developer with prior PayPal API integration experience and a library of previously used code - It could be as easy as packaging up your previous work with a few small amendments, as what I require is very common for subscription based websites.

I need the PayPal API to be integrated into an existing website (all details required for the job and associated files will be provided to successful applicant) however, will only require a fully working example (standalone) which I can test locally. Once the coding is done, reviewed, and approved on my localhost the project will be done. You won't need to port it to a staging or live server. You will be provided with the table definitions required to allow live db integration.

This project consists of three deliverable elements:

1) A single MySQL table (Payments Table) to hold all subscription information from PayPal allowing multiple date based subscriptions per user ID.

2) In asp.net 4.0 and Visual Basic - Create a single Payment Page (Payment.aspx) using provided master page template. Payment Page should request and validate all required information for subscription at PayPal using the PayPal API. Send this information via API, without leaving local Payment Page, user then enters credit card information or logon details to confirm subscription with PayPal (without ever leaving Payment Page perhaps an iframe?). Once payment is confirmed, Membership level (Int) should be inserted into Profile Table in db to make user’s membership level (1-3) valid immediately.

3) Require a way to query PayPal API and Payment Table on a daily basis to cross-compare and ensure the user has the correct monthly membership level for the amount of subscription paid. It needs to take into account the initial 30 days FREE trial period and whether the user has renewed for 30 days or cancelled. Any monthly membership cancelled by the user should be set to 0 in the Profile table once the membership period has expired.

Must include ability (in code would be fine) to switch to ‘sandbox’ for testing with PayPal's sandbox environment.

Your proposal must include the subject line as ‘MyJobs PayPal API’ so I know you've read this! Please also advise in your proposal how you would, in principal, provide the scheduled API querying.

Any code and SQL scripts submitted will remain the property of the company commissioning. It would be expected that the code is well structured and well commented for future maintenance. There may be a requirement to verbally explain parts of your code to a developer on completion.

Additional or on-going work may be available to the right candidate in the future.