if you want to do a special condo for your brothers birthday then create one with canvas items. for example use canvas statue with an image of a balloon and make a few canvas cubes with a present texture. plus you can add some fireworks or other stuff. if you need money. just play minigolf or other minigames a few times and youll get over 50k units.
I think they wont and / or cant that in 5 days just for a few items which you suggest. they have much work to do. but the idea with the cake is not bad.