]The gardening mini-game gives about 800 to 900 Bun-Buns depending on accuracy which takes about 1 minute vs playing the basket ball mini game which can give maximum of 300 Bun-Buns without failing before getting your first shot which can take 50-60 seconds if you're good at it.
Hide and seek gives you 120 Bun-Buns Bun-Buns in 60 seconds and about 240 Bun-Buns if we go to the per minute (not including the 3 second timer at start).
And then 90 Bun-Buns in 30 seconds (180 per minute) for the Rock-Paper-Scissors Mini-game. Planting flowers gives the highest and going into the menu takes 5 seconds to refresh back to the mini game either using save state right before (pressing continue) or going into acts and porpoising act 2 and gardening with Skye.

Should take about 10-15 minutes to get 10k Bun-buns, Good luck Gambling!