Your definition of exclusive doesn't totally match Merriam-Webster and sorry, but I give them far more credibility.
There's no "might mean" to it on the number purchased. They are limited, according to the company which makes them and we... don't matter.
Since the manufacturer limits things like who can sell them or how many will be built, they are instantly exclusive in cases like the ZL1 or Z/28. There's much more than just cost.
There will be 137 GT350's and 37, not 47, R models for 2015. 37 was chosen in memory of Carroll Shelby, who insisted that along with 2 prototypes, he built 35 1965 Shelby GT350's... which somehow won the SCCA B Production national championship.
37 or even 100 absolutely does meet "exclusive" in terms of automobiles and nothing you can think will change that.
LACK OF AVAILABILITY defines the word "exclusive" even more than "cost" defines it.
Exclusive: 1 a : excluding or having power to exclude b :
limiting or limited to possession, control, or use by a single individual or group. Apparently that "person" is both of you.
If you've seen more ZL1's, you're in an area where more are on the roads, etc. The 1LE is far more successful and... less exclusive in terms of sales.