As previously stated, quality server's and ram are not cheap, but unless it's some rare form/spec, the prices are not that extreme. There are other costs though that are considered by companies when setting their pricing.  Employees' salaries, electricity, air conditioning, rent, etc.  

But I do agree, when you see 2G DDR3 for $60(CDN) and then your hosting company wants to charge you $10/mo for 1G DDR2, it seems a rip off.

You said it yourself though, they are there to make money.

why do hosting co charge so much just for RAM?
I'm busy writing my first plugin, using PHP 5.3.5. I come from a C# environment, and I must say I'm more than happy with the level of support for good, solid OOP techniques in PHP. However, I'm a little uncertain how to structure a plugin using classes. I have a plugin class that takes care of hook registration in its constructor, and some worker classes like a mail queue and mailer, but I have one or two non-class scripts, mostly for forms, that I don't quite know how to neatly fit into classes. What resources are their I can consult for guidance on this aspect of my OO plugin?

The plugin is for mass mailing, i.e. mailing to all subscribers, on schedule etc. It registers a custom post type for mail templates, with add new and edit capabilities, and it adds its own menu to the bottom of the admin menu, currently with two submenu pages: 'settings' and 'send mail'. It also adds an 'opt out' option to the user profile page, but that's quite tidy and easy to include the main plugin class.
