would it make sense to back as a new supporter (say at blood named): get all the extra loot (b/c I kinda want another set of dice and shirt, and more mechs-- esp ones I didn't pick this time around)
Or
Just add on to existing pledge?
of course, all is dependent on finances at that time.
if your selection of addons comes close to the content of a pledge level, you always have the better deal with adding the additional pledge, even if it contains some stuff that you don't need. In particular piling up mech addon boxes isn't worth it given they notably higher price point.
Of course there are exceptions to the rule, for example if you want multiple of a specific item, e.g., t-shirts, then it would be a bit expensive if you want a dozen of them. ;)
