How much to pay for something in around ex/ex+? Anyone know a good seller? Tempted to grab or wait to grab one from Keh.com but I'm open to alternatives. Is there any mount type that is of greater or lesser difficulty to adapt to M43? Anything that influences final magnification noticeably through the adapter depth? Can the 1:1 adapter be substituted through using ordinary extension tubes? If so, what are the ones to get to do that? Is it worth doing something slightly weird like Bokina (whatever mount) > OM adapter > OM Telescopic Auto Tube 65–116 > OM/M43 adapter? Any serial numbers to try to get or avoid?