Sometimes all you need is to encrypt your web traffic. Here's some services that may be useful to you:

SSL2Buy has a discount for AlphaSSL Wildcard for $42/year. Instructions are spotty, but you can get by with this DigiCert documention.

Once installed, you should use one of these free services to validate that your SSL certificates were installed correctly and notify you of any potential known holes in your security:

• SSL Labs' SSL Test
• SSL Shopper's SSL Checker
• DigiCert's SSL Installation Diagnostics Tool
• Global Sign's SSL Configuration Checker