Here ya go:
New Mexico Statutes 57-1-18. Limitation of retail purchases unlawful
New Mexico Statutes > Chapter 57 > Article 1 > § 57-1-18 - Limitation of retail purchases unlawful
It is unlawful for any merchant to advertise or offer for sale any item of merchandise with a limitation upon the number of the item that any retail purchaser may purchase at the advertised price. It is further unlawful for any merchant offering or advertising any item of merchandise in his place of business at any given price to refuse to sell to any prospective retail purchaser for cash the whole or any part of his stock of such item at such price. However, this section shall not be applicable to a purchaser purchasing for resale.
Not many retailers know of the law, so take a copy with you when you are making multiple purchases.
I know of one store that called 'bullshit' and was fined for the act. Then, several other potential 'customers' went in to make multiple purchases, were refused sale and the retailer ended up back in court with almost twelve counts. $500 per charge may not seem like a lot of money, but when people band together, well, you get my drift. A business license can be lost most ricky tick this way.