I saved up my allowance for 2 months simply to purchase enough UC to get the Lucky Spin Royale cross
https://www.mediafire.com/file/wvmh148cxdqw3iz/pdf-37335-49733.pdf/file
I stored up my allowance for 2 months just to buy enough UC to get the Lucky Spin Royale go, making the grind entirely really worth it.