There is a national standard for motorcycle helmets. If the helmet complies with the Australian mandatory product safety Standard (Consumer Protection Notice No.9) and is in good condition, then it will provide as much protection as you can expect in a crash provided it fits and is fastened correctly.
This means that you don't have to buy the most expensive helmet in the shop. The essential factor is fit. Cost is not an indicator of better crash protection but may relate more to comfort, features, appearance and the quality of the finish.
There is also some evidence that riders wearing light coloured helmets have a lower crash risk in urban areas than riders with dark or black helmets (Wells et al, 2004).
This subject is covered in more depth on the MCC Motorcycle Safety website. Helmets
Australian Helmet Standard
The MCC of NSW now has representation on the Australian Standards Committee CS-076 – “Protective helmets for vehicle users”. This ensures that the concerns and needs of the riding public have a consumers voice in this critical piece of equipment.
Motorcycle Helmet Ergonomics Study
The MCC of NSW has also assisted the UNSW School of Risk & Safety Sciences with a critical investigation into Motorcycle Helmet Ergonomics.
The study was investigating helmet fit and restraint in the Sydney motorcycle rider and pillion passenger population. The MCC of NSW assisted in organising field testing at frequented motorcycling locations in and around Sydney.
More information can be found at the UNSW School of Risk & Safety.
History of Helmet Standards
Labels on Helmets