If the law simply prevents prices higher than $100 in Illinois then manufacturers and distributors might stop selling in the state or only take orders from the state if they have surplus. Either of which might hit availability in the state, especially if the industry tries to make an example out of this.

I guess it also depends on the profit margin at that price and how it compares with the "market price".

Edit: Care to explain the downvotes? I'm just putting forward what could happen in the real word, not voicing my opinion of what is right.