Yes I know exactly what you are saying and it all makes great sense. However not only do most of us here not have those great opportunities (as I said, 360s are very sought after here, and getting very rare too, we only got that engine for a few years in a few models. We just don't have the numbers that you do) but especially in my city, which is very limited compared to Sydney Melbourne Brisbane (all East coast). Also, I don't WANT a 360 or 318. I had both of those, as I said, I sold the 360 because it was too big for what I wanted and I got all my money back so basically got the car for free minus the engine. The 318 I had went into another vehicle. The 340s are both earmarked for my E bodies. I had the 273 lying around and want to use THAT one as an economical daily driver. And in any case, it hasn't cost me a heap, and i had some parts lying around that suited that engine well. Also I have never had a 273 and now I will have one. It's not the ultimate power I want or need (have more Mopars for that). I just want a nicely improved economical 273 for my ute. Hope you understand.
As an example of the differences in prices, about 11 years ago I bought a complete and running (but unknown condition) 360. Came out of some imported US car. Had all the fruit: ignition, alternator and Holley carb. I paid $2000 which was a very good price at the time! And this was 11 years ago. I was lucky, all except one bore had very good compression, that turned out to be a burnt valve which I replaced. New head gasket, Sig Erson 290 Cam and better springs, new DRTC, single plane Weiand and a TQ plus headers and twin system and that engine in my Challenger was a great engine - I took it up to 130mph and it was still accelerating (the 2.6 diff helped there).