The Game -- That Wedding Snafu Cost Me $100k

The Game is psyched his wedding is back on ... but his wallet, not so much ... the rapper tells TMZ rescheduling his cancelled nuptials set him back a cool $100k!!!!!

We caught up with Game and his fiancé Tiffney Cambridge outside Hennessey's Tavern in Hermosa Beach this weekend ... if you recall Cambridge pulled the plug​ on the couple's wedding back in July, but then changed her mind.

In the video ... Game -- still sporting a broken thumb​ -- says they DID reschedule the ceremony, but it wasn't all smooth sailing.

Game says all the venue changes cost a whopping $100k ... but you gotta check out his reaction to the setback ... 'cause it's PRICELESS.