Why do full suspension bikes seem to be on average £1000 more expensive than hardtails? I was just looking at the new On One Codeine full suss mountain bike and 45650B hardtail (£2599 vs £899) respectively. However, what is the great difference apart from the shock? A fox rear shock goes for about £300 max. What causes the giant price difference?
I don't think you are matching like for like and actually the price differential is quite small.

The only fair way to compare two bikes is by looking at the frame only price. In this case I've been unable to find the frame only price for the Codeine (SingleTrack forum suggested £599 with Monarch R vs £225 for 456) so have used Santa Cruz instead:

The frame only price for:


The hardtail Highball is $750USD RRP
The full suspension Superlight 29 is $1,099USD RRP with a Fox CTD


Both are XC bikes, 29" and alloy.

So the price difference between the two bikes is $349, this would include:


the shock
the pivot bearings bolts etc
additional welds for the FS
additional strengthening for the FS
more complex manufacturing of the pivots
additional design costs


There are other factors that influence the price of a complete bike that may explain the difference between the 456 and the Codeine. The £899 45650B is an intermediate level specification whilst everything I have seen on the Codeine indicate it will have a high performance build. The differences from what I've seen include:


the 45650B has a Deore groupset, a XT or X9 groupset would be £300 cheaper but the Codeine prototype had an XX1 groupset which would be at least £500 more.
the Codeine may come with a dropper post which would be £200 more.
the 45650B has a Sektor fork vs the Revelation on the Codeine which would be £100 - £200


Comparing the two bikes side by side there would be more examples where the specification levels are different and would justify additional costs (brakes, wheels, tyres, bars, saddle etc.).