Ok lets try to shed some light on this.
Blurblock, much as I am all for consumer rights and everything, I regret to tell you that legally speaking, its doubtful that you have any legal recourse. As most have said, the equote is likely to be taken as an invitation to treat rather than an offer to sell. (will have to see the equote then can be sure but not likely to change the interpretation).
That said, the recently enacted Fair Trading Act does provide that you can get the supplier for unfair practice if he "represents that goods are available for a particular price if the supplier knows or can reasonably be expected to know that it is not so, unless the representation clearly states any limitation". Well, i also think its unlikely that you will succed on this point, and after all, why bother to institute a civil action for just $30? After deducting the small claims fee of $5, filling up the forms, attending the meditation, attending hte hearing, and the transport cost of all the above, i think you pretty much dont have much else to do.
That said, if your story is true and you can back it up, you can also post further details on the shop (although most have a pretty good guess), wat was in the equote, the salesmen's reaction when you produced it and his reasons for not honouring the equote etc. You may also try to speak to his supervisor or the manger of the shop to request for an explanation.
Hope this helps.
.... hehehehe 