Earn 10,000,000 guilder. A coin purse filled with...a ton of money!
The final Guilder-related trophy. This is also one of the most time-consuming trophies in the game and as a result, one of the last trophies many players will earn before aquiring the Platinum. As daunting of a task as this seems, your ability to obtain it isn't going to be extremely difficulty but rather, time-consuming. Good resource management, conservative spending and a devotion to maintaining the consistency of said efforts is what will bring you closer to this trophy. Aside from that however, you still probably wont obtain it until you're GR11+, give or take. This will be largely dependant on a number of factors including but not limited to;
How much you've spent developing your Georama.
How much your equipment is worth (enhancements and upgrades included).
How much your overall inventory is worth (Item Storage).
How much raw Guilder you've aquired (through questing and other means).
The "fastest" and "easiest" way to obtain this trophy is to aquire at least 5,000,000 Guilder then use the Save/Reload method mentioned previously. In most cases, you may not have enough to unlock the trophy. But attempting to do so will give you a clear idea of how much you do in fact need to obtain it. Again, reloading the save file will not affect the trophy. It saves to your PSN ID and WKC Home Page. It's a huge benefit as well in that once aquired you can focus your money on other things, like Georama development and Binding. It also eliminates the burden of having to save up 10,000,000 in raw Guilder, which in and of itself is a behemoth task for the majority of WKC players.
Aside from the method described above, you're free to pursue whatever methods you establish for yourself early on. However the most efficient way of getting this trophy is to use the Save/Reload method. Just ensure you save the game before selling off everything then reload the same save immediately after syncing to the servers.