The official timer for competitions is the SpeedStacks one, which you can find on their website. However, you can buy a cheaper one, which you can find at the link provided.
There are many places where one could buy a timer to control a light switch. One looking for a timer to control a light switch should visit popular on the web sources such as Lowe's, Intermatic, and Honeywell Store.
You can only buy timer balls in rustboro.
you cant get a timer ball in emerald
there is no timer ball in leaf green
There are many places where one could purchase a timer for the game of chess. The best to look for chess timers would be electronics websites like Amazon.
You can buy timer balls at Canalave city and at the Pokemon League.
buy them+
You can get a Rubik's cube in the nearest Toys R Us shop, or you could order one from an online store such as Amazon.
rustboro city
You buy them in rustborro city
any
You can't buy those, i think.