Part selection help..

[dannydavi]

I know this is basic stuff that doesnt matter to much but i just want a better understanding of brands and pricing expectations so take a look and tell me what you think.

here is the address to my shopping cart.

http://www.autopartswarehouse.com/basket.php

the two struts in there seem the same, but two of one are about the same price as one of the other... i dunno the difference, the pic displays dif accessories..

the oxygen sensors are same manufacturerbut 20 bucks dif. according to pic, it looks like one comes with flange and gasket and other doesnt... is that important? i would think yes, but then why would they sell them without?

and the fuel filters, it looks like one is double the price and it comes with a bracket, dif manufacturers... but i just want to know why prices for things like these vary so much..?

oh and spark plugs... those good ones? i heard someone talking about NGK plugs before, these are the iridium IX supposedly.

any info helps, i do need to replace all of the above, so if you know better ones or tips on what to look for when buying or replacing. thanks.