Around 200k is the initial basic investment in attachments, if you buy all the vendor ones plus a few basic ones from the AH (Flashbulb, basically, but maybe some of the tier II stat increasing ones, like Tension spring II). Then when you start partying you'll want all the acc and attack ones.
As you level, you'll need some moderately priced pieces of equipment, but nothing really different from most DDs. You'll want to have most if not all the attachments at 75, and that's when the big investment are: there's 3-4 in the 600k-1.1M range.
I'm currently saving for a Turbo Charger which has skyrocketed to 900k on Ragnarok, and considering my moderate weekly outcomes, it's being a pain ;_;
Frejan - Ragnarok
SCH 99 PUP 99 WAR 99 RDM 49 NIN 49 SAM 49
Windurst Rank 10, ZM+CoP: The Last Verse, ToAU: Eternal Mercenary, WotG Champion of the Dawn.