It seems extremely expensive when storing struct type

Question

In my contract, there is a struct type:

struct Claim {
    address healthcareProvider;
    uint amount;
    bool patientSig;
    bool paid;
    uint item;
}

And the initialize function is:

function MakeClaim(uint _amount, uint _item, uint num) {
    Claim memory c;
    c.healthcareProvider = tx.origin;
    c.patientSig = false;
    c.paid = false;
    c.amount = _amount;
    c.item = _item;
}

When I call this function to create a new Claim type, I find the price is 2.687 ETH (not gas). This is much more than the cost for deploying the entire contract! I am testing it on the Morden test net. Where is my problem?

Answer 1

As in blockchain data-store is a scarce resource, it's pretty expensive. Storing data is the most expensive operation in any smart contract.

sstore  100     Paid for a normal SSTORE operation (doubled or waived sometimes).

You can see the whole list: https://www.cryptocompare.com/coins/guides/what-is-the-gas-in-ethereum/

So, if you are using complex structures, the cost is multiplied.