Most expensive? A toss-up (I would have to search for receipts) between my 600mm Nikon F4 ED and my 50mm F1.4 Summilux M Asph. Best deal? A virtually spotless ( even the manual was unwrinkled and the box and packaging look like they had just come off the shelf) F5 for $212.00 USD off ebay last fall...or maybe the F3HP I scored last month for $70.00 ( also with all the original packaging)? There again, as Matt King says, APUG membership - the opportunity to access the brain-trust one H..l of a bargain!