Buy/Lease E500/CLS500

Hi Guys,
I have 2001 C320 Sport and thinking of upgrade.
Dealer offered new 2005 E500 bl/charc with Premium package, keyless go, rear seat package and trunk closer for about 61500 before sales tax + 2500 for a new phone system (phone included).

LEASE OPTION $818/mo with $0 down. 39 mo lease. About $35000 purchase price at lease end.
I drive about 10000 mi/yr

BUY OPTION $976/mo @ 6% for 60months $18000 downpayment.

Also I really prefer CLS i even put deposit in summer. Price with premium package and phone is about $74000 before sales tax.

I dont know exactly what it costs to lease but i would imagine about $900 month/39 mo $0 down

BUY OPTION $1076 month for 60 months with $23000 down.

I would appreciate any input on lease/buy which one you would pick and how quickly you think CLS and E500 will depreciate.

I already lost about $9000 in a year on c320 i bought it a year ago for 27000(before tax) and now dealer offers for it 18000. So I'm thinking that get $13000 equity back from c320 and lease E500/CLS with $0 down may be not a bad option.

Thanks a lot,
Plato