Where to purchase single turntables?

Unfortunately, it seems that the turntables come in pairs, with no option to customize which turntables we actually need.

This is unfortunate because one of our plans for a little test include several small turntables, with the large ones rendered useless for this task due to their silly mounting holes.

Is there a way or place to purchase just one type? I don’t want to spend a load of money and end up with useless parts lying around.

I don’t know of anyway to purchase individual turntables. What I have found is that different robot designs will use different turntables, the ones you buy and are unused this year may be exactly what you need next year.