i bought an automatic 4X2 X and regretted every moment that i did not shell out an extra three grand for a 4X4. what is better, convert it to 4X4 or trade-in? does a conversion kit even exist?

The quickest reply: trade-in.

A little discussion on the matter:
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=7;t=000051

Xterraparts priced it for me at about $6000.

TRADE!! .. its MUCH easier, and you get a full warranty on the powertrain, you convert yours and it would void your whole damn warranty!

$3000? Where are you, Canada? It's $1800 in the states....

huh?.. i thought a 4x2 could go everywhere and anywhere just like a 4x4?....oh wait, no that was a dream i had!