I found the same thing as you Mike.
Cheap spray bottles don't last too long at all and I'm starting to think the only really good ones are the more expensive ones.
I've bought them from a local Industrial Plastics shop but even those sprayers can be a bit flakey.
That said, I've been really impressed with the spray bottles that come with Eco Touch products. (Eshine). Get a couple of the waterless wash spray bottles or the quick wax products and hang onto the spray bottles, they're winners. They put out the finest mist I've seen coming from a spray bottle ever. They just work like I think a spray bottle should work, and NOPE, I'm not selling you my empty ones.
Check out the Kwazar spray bottle also from Eshine. It sprays on the squeeze and the unsqueeze. (is there such a word?) It's a 1/2 liter bottle and should put out huge volumes of product so I'm thinking it'll be perfect for waterless washes, QDs, wheel cleaners etc. I've got one coming and I'm getting a bit antsy to try it out.
Good luck,
-John C.