Liz,
Yes, they are an expense, but..................they are certainly worth it!!
I bought my 12"LB three years ago before they made the current changes.
It was a royal pain in the @$#%^ to collimate either the primary or secondary mirrors, plus it would take forever!!
There was also a chance of dropping your screwdriver onto the primary whilst trying to collimate the secondary.
Spend the money Liz, it will be well worth it.
I bought my knobs from
http://www.astronomy-shoppe.com/ go to the "Dob Kits" section for the information.
