Any tax professional worth his/her license should investigate your CSEDs before tackling the full resolution of your tax debt. You never know: your debts might just disappear. Tax debts expire generally TEN years after they are assessed.
I have one client in North Dakota where we are waiting out the expiration of one of his debts (his 1996 tax debt expires on October 18, 2009). The case actually has a Revenue Officer assigned. But the CSED is the CSED. Once 10/18 passes, the collection process is over for this particular debt.
Way back when, the IRS would bully you sign to sign a waiver of your CSED -- particularly when you entered an installment agrement. But those days are over -- since the 1998 Reform and Restructuring Act was passed.