The way to farm this is on the first speeder mission in the canyon with Ashoka and Anakin. On the second challenge, where you have to collect the blue point orbs, simply keep replaying this over and over until you reach until you have enough money to buy the x3 multiplier in the store. Then just keep farming the points until you have enough to buy all the items. You do not need to worry about the items with that cost relics as they do not count towards the achievement.
If you can have a second player (either keyboard or WIRED controller) it'll make this go a little faster as they won't try to collect the orbs like the AI partner does.