I'm a tightwad. I freely admit it. I also don't have any truly rare or expensive machines to show for it. Like anything else, truly good quality and rare machines are worth the money. If that first A.F. Johnson machine shown is all original, it may well be worth the money to a serious collector. The condition is excellent and how many in that condition are still floating around? The second tightwad example is closer to my budget at the moment and certainly isn't in nearly as nice of condition but if you want one of those machines it can get your foot in the door anyway.
The Kenmore may be a 15 clone but a diehard Kenmore collector may be willing to spend the money. I don't think 15 clone Kenmores are terribly common, at least by modern standards. I would be interested in the source code on it. Is it still a "White" machine or is it ordered directly from a Japanese manufacturer? If a White, then it would be an interesting machine in the sense that White had started buying machines instead of manufacturing them but still had the contract for Sears.
Rodney