Amazon Annoying

I've recently wanted to buy a couple of xd cards. No problem, on to Amazon, ooh, good price. Add to basket - more than enough to qualify for free delivery. Checkout... click... click 10 quid postage?! For two items the size of postage stamps?

It turns out that I'd clicked on an item supplied by a third party vendor, and with these, unless you go digging, the postage costs can be a bit of a shock (it is possible to find out in advance, but it's several clicks to find out - and you have to know where to look).

I've had third party suppliers through amazon before, but sometimes I'd just like to turn them OFF. If I qualify for supersaver delivery, I'd rather pay the 6 quid and get that extra item with free postage, instead of 5 quid and have to pay a delivery fee.

... and sometimes, I just want to know who I'm dealing with!

I know I can select which vendor to use on amazon, but is there a way to limit searched to particular vendors? e.g. 'Amazon only', or '98%+ vendors' only ... or 'vendors who don't rip off with the postage costs only'

Is there a way to do that?

Hassles with multiple vendors for one batch of items is really putting me off amazon - the 'click to add to basket' has become 'check that you're buying from the same person to add to basket, so that your order isn't liable for multiple extortionate postage costs'