Getting decent quality prototype breadboards for a reasonable cost is something that has eluded me for years. I think I have finally found a reliable source. Those advertised on eBay or at least the cheaper ones seem that I have previously purchased too often have poor metal connectors inside. It can be difficult to insert pins in and if the pin is thick the contacts don’t completely spring back. I have not found a way to determine which of these are ok as just looking at the breadboard doesn’t seem to be reliable method.
The new ones I’ve got are BB830 by BusBoard. I found out about them by Ben Eaters in this video. Skip to about 1:18 if you want to hear him talk about them.
Ben sells them and has more information about them on his breadboard page, however I must confess I got them from Mouser as I am outside of the US and was preparing an order with Mouser anyway. Here is a shot of a bread board fastened to a cheese board.
I’m very happy with them. They cost more than those I’ve previously purchased on eBay but if they don’t work then any price is too much. Also, I want to support producers of decent quality items. So far, I’m very happy with the BusBoard ones.
Garry's blog 
Completely agree I have tried many others from Amazon etc and the quality is always very poor on springing back, after a couple of insertions the contacts become very loose. The BusBoard BB830 are the only ones that I have found (so far thanks again to Ben) that are worth the money. As I’m outside the USA I also went to mouser
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