Since the anime has rekindled my interest in the whole franchise, I've decided to keep a running tally on how much I've spent overall on this franchise.

Pre-Anime airing 2011
Iori Minase Figure - $30
Iori Minase Figure - $40
Iori Minase Figure - $87
Idolmaster Platinum Hits (Xbox 360) - $40
Idolmaster Live 4 U Platinum Hits (Xbox 360) - $40
Idolmaster SP: Missing Moon (PSP) - $55
Idolmaster SP: Wandering Star (PSP) - $55
Idolmaster SP: Perfect Sun (PSP) - $55
Idolmaster 2 (Xbox 360) - 8200 yen (~$99)

Post-Anime Airing
Dengeki Hime Extra Issue IDOLM@STER Official Magazine, IMAS For You! - 1950 yen (~$25)
Makoto Kukuchi keychain - x2 - 615 yen - 1230 yen (~$16)
Miki Hoshii keychain - x2 - 700 yen - 1400 yen (~$18)
Idolmaster Cheerleader A3 Desk Mat - 952 yen (~$12)
Idolmaster Vol. 1 Blu-Ray + Idolmaster 2 PS3 game bundle - 16971 yen (~$218)
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Xbox Live 1600 points (used for iM@S2 DLC) - $25
Ready!! (Animation Master 1) CD - 1543 yen (~$20)
Animation Master 2 CD - 2667 yen (~$35)
Animation Master 3 CD - 2667 yen (~$35)
Xbox Live 3200 points - $50 (only $25 was spent on iM@S 2 DLC)
Xbox Live 1600 points - $25
Xbox Live 3200 points - $50
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Change!!! (Animation Master 4) CD
Idolmaster BD Vol. 2 + Gravure 4 U vol. 2 - 8260 yen (~$106)
The iDOLM@STER Master Artist 2 - First Season - Miki Hoshii CD - 1457 yen (~$19)
The iDOLM@STER Master Artist 2 - Fist Season - Chihaya Kisaragi - 1457 yen (~$19)
Idolmaster BD Vol. 3 + Gravure 4 U vol. 3 - 8260 yen (~$106)
Iori and Miki 3D Mouse pad - x2 @ 750 yen, 1500 yen ( ~$20)
Hibiki and Makoto 3D Mouse pad - x2 @ 750 yen, 1500 yen (~$20)
Group Swimsuit Large Mouse pad - x2 @ 420 yen, 840 yen (~$11)
Dengeki G's Festival Comic vol. 2 (comes with a Miki microfiber towel) - 2980 yen (~$38)
Idolmaster 2 Colorful Days manga - 570 yen (~$7)