Any set value in the eVar will be captured for sure. If you use 'Occurrence' every eVar you set will be displayed at the Reports Interface.
And, yes, eVars by default have Last Touch Attribution for all the Conversion Events. If your visitor selects the Price $500, changed to $600 and then to $700 to trigger the purchase event. $500, $600, and $700 will be captured against the 'Occurrence' metric and only $700 will be captured against the 'Order' metric. So, the Last Touch Attribution is for Conversion Metric / Success Event selected during the time.