Please Explain This Valuation

Agreed. Remember, there were no official mint sets in 1967 or 1968, so no coins were automatically put aside in pristine condition. Any Unc coins around today were pulled from circulation.

There would'nt have been anywhere near as many collectors back then so less coins saved,all early decimals in high grade are worth OK money,some are worth a motza ( lots )

There were collectors back then, but they weren't collecting decimals. Pick up a typical copy of ACR from 1968, and it's full of articles on predecimals, predecimal varieties and world coins. As an example, here's the list of articles in the August 1968 issue:
- Decimals Only in New Zealand (NZ demonetizes predecimal coins)
- New Zealand Coin Sorting Machine a Winner (about a NZ-invented machine to quickly separate silver from cupronickel coins)
- $5m in Buried Silver (estimated amount of Aust. silver coinage "lost" in the New Guinea highlands)
- Plea for Australian Proofs (suggestion to retrospectively issue 1967 and 1968 proof sets)
- Upsets (how to detect and measure them in the predecimal series)
- Pricing Australian coins (mainly a diatribe against dealer practices, with a suggestion to establish something resembling a TPG)
- Nigerian Rebels Issue Notes (Biafran banknotes)
- New Nickel Coinage for Canada
- Royal Canadian Mint Report

Only one article about Australian decimals, and that was about proofs, not circulation coins. After the hype of 1966 was over, nobody cared about them for a few years, not until there were enough of them to consider a "collection".

I understand about the collectors part and all but I'm just so surprised that one year can make soo much difference, its understandable why you would want a 1930 over a 29, but wouldnt people rather the coin in same condition with less than half the mintage and only a year between?

Thanks biggfredd!