I currently have 220VAC coming into our house. I would like to install a Manual Transfer switch I can hook up my 6KWatt Generator up to using 220VAC. What is the cheapest option...all I can think up is a DPDT switch...

Countrybear,

This is a DIY question.
When you registered with ECN the Board Rules were posted, as follows:
"Please understand that this Discussion Forum is meant for the benefit of those in the Electrical Trade and other related persons. Although related discussion by others may sometimes be permitted, questions of a How-To nature by untrained people (aka DIYers) are not within the scope of this Forum"

Sorry

You really can't use a normal switch, it needs to be listed transfer equipment but electrically it is a DPDT switch.
How much work/expense involved is mostly limited by how your panel is laid out now and how much rewiring you are willing to do. The easiest from the user/operation standpoint is to move the circuits you want backed up to a sub-panel with a transfer switch in it.
Some styles of main panels will take a transfer interlock device that works with your existing breakers but you will be responsible for your own load management.
If your main panel has a back fed breaker main directly across from a spare slot the cheaper interlock will work. When you start getting into interlocks for top mounted mains they start getting expensive, usually more than you can buy a transfer panel for.