Oblivian: And rightfully add this in their T&C of using the site too..
We can change our prices at any time before accepting an order. Also, we can change our prices without prior notice.
Errors and Omissions (Mistakes!)
We pride ourselves in getting things right, but sometimes errors and omissions (mistakes) might occur with any of our advertising, quotes, invoices or acknowledgements. Sorry. Due to our administrative processes, mistakes might be discovered up to 30 days after the goods are delivered to you. If we discover a mistake we’ll let you know promptly, and give you the option of retuning the goods for a full refund.
and if you (as the buyer) clicked a button or a tickbox saying i accept the linked terms and conditions while checking out your order, you are therefore agreeing to them and they are enforceable.
if the T&C's are just a link on the bottom of any webpage, then they are deemed to be inadquately provided and therefore its unreasonable to enforce them
IANAL, btw. Just remember reading an article on this.