Between Easter 2010 and 2011, dairy prices increased 21 per cent, cocoa prices 10 per cent, and sugar 55 per cent.
GST increased and oil prices also rose. That pushed some items up from about $10 in 2010 to $14 in supermarkets in 2011.
Since then, commodity prices have levelled out and dropped in some cases. Dairy and cocoa prices have fallen significantly.
That, combined with the strong dollar, should have brought Easter egg prices down.
But prices have stayed the same. Last year, a Cadbury supermarket hollow egg packaged with two chocolate bars, such as Moro or Pinky, sold for $13.99 or $10.99 on special.
This year, Countdown is offering the same special, although a Roses egg retails for $15.99.
"The currency has been stronger in the past 12 months so imported ingredients should be cheaper," Harris said. "That's not reflected in prices but might help manufacturers' margins."
He said the size of eggs had also dropped. "Eggs are now 85g instead of 100g ... it's margin for manufacturers but consumers need to be aware."
A Cadbury spokeswoman said the firm had long lead times for cocoa purchasing.
"Short-term fluctuations in commodity pricing do not have a substantive impact on our pricing."
She said egg sizes were based on customer demand.
Easter egg packaging is bigger and better than ever this year. Kirkaldie & Stains in Wellington is selling a 750g egg for $79.99 and even The Warehouse is offering a 600g $24.99 3D Dragon Egg.
But the most exciting packaging does not necessarily equal the best chocolate deal. Most of The Warehouse's novelty boxed eggs contain a hollow egg and some sweets.
The hollow egg is the same as one that retails loose for $3.99.
But when eight chocolate coins are added and it is boxed up and called a Pirate Egg, the same chocolate sells for $8.99. Some of the biggest eggs on offer, such as the hollow Dragon Egg, selling for $24.99, left their boxes at least a quarter empty.
Shopping around can get you better prices on Easter eggs. Name brands attract a premium.
We bought a no-name 130g egg with chocolate buttons from The Warehouse for $5 this week. A Cadbury version with a 105g egg was selling for $6.99 at Countdown.
But cheaper chocolate contains more sugar and less of the cocoa solids that are said to provide the health benefits of chocolate.
The hollow eggs sold by The Warehouse are manufactured in New Zealand and contain 2261 kilojoules per 100g of chocolate, 5.8g of protein, 31.3g of fat and 56.9g of sugar.
Sugar is the largest component. Cadbury chocolate has 2115kj per 100g, 6.1g of protein, 25.7g of fat and 53.3g of sugar.
Lindt chocolate, which has eggs selling for $10.99 at The Warehouse, contains 2180kj per 100g, 8g of protein, 40g of fat and 28g of sugar. Cocoa mass is the largest component.