SharePoint Price Calculator

http://community.bamboosolutions.com/blogs/sharepoint-price-calculator/default.aspx

Microsoft Office SharePoint Server 2007 and Related Technologies pricing

http://office.microsoft.com/en-us/sharepointserver/FX102176831033.aspx

SharePoint 2003/2007

Developing Custom Applications by Using Excel Web Services in SharePoint Server 2007
Adding Excel Web Parts to Pages Programmatically in SharePoint Server 2007

Downloads

SharePoint Server 2007 SDK: Software Development Kit
Visual Studio 2005 extensions for .NET Framework 3.0 (Windows Workflow Foundation)
Windows SharePoint Services 3.0 Tools: Visual Studio 2005 Extensions, Version 1.1
SharePoint Products and Technologies Templates: Web Part Templates for Visual Studio .NET

InfoPath

Developing InfoPath 2007 Managed-Code Solutions
How to execute JScript code from an InfoPath 2007 browser-enabled form template
Designing InfoPath Forms for Workflows in SharePoint Server 2007