It doesn't matter which prices you choose, old money will always outperform decimal because it has more factors. There are advantages and disadvantages to both but quibbling about the price of eggs isn't going to change them.
You liked the egg example until I pointed out how daft it was. Ah, the fickleness of youth!
It's also not going to matter only at the point a dozen eggs is a pound, but this is well off the original point and I'm not interested in a position that, strangely enough, means decimalisation has no impact. 240 pennies is 240 pennies, after all.
Try to think things out before hitting "reply". It would improve your posts immeasurably.