I stored up my allowance for 2 months just to buy adequate UC to get the Lucky Spin Royale cross
https://elliotubby411.raidersfanteamshop.com/buying-uc-for-the-royal-pass-season-topping-up-small-amounts-on-manabuy
I saved up my allowance for two months simply to purchase enough UC to get the Lucky Spin Royale go, making the grind fullyyt well worth it.