Whats bad is that whether or not it is a typo, it will hurt everyone. People will get it stuck in their mind that they can get signs for $36.50.
From time to time I have had customers who come into our shop and to be shocked by how much we charge for screen printed yardsigns. As often as not they claim that they saw some yard signs advertising yard signs" "500 for $500". Now personally, I have never seen such an advertisment, but I have no reason to call the potential customer a lier. I don't know where they saw that advertised, but for whatever reason, they have it stuck in their mind they can get yardsigns for $1 each, and that is all they expect to pay. So I have to waste my time with the customer, deal with the frustration of the customer, and sometimes be accused of "ripping people off" (sometimes in front of other customers) - with virtually no chance of making the sale.
I have this one customer, he thinks that he is helping me, but he keeps telling people about our increadably cheap prices. They call us, wanting stuff at prices that we can't honor, and of course then they get mad when we dont honor the prices. The irony of this situation is that this particular customer manages to get a premium price for the products that he sells.
At this point, after seeing those postcards, the industry as a whole may loose a few sales because people who would have otherwise had no objection to paying $365 now will feel "ripped off" at any price over $36.50 and will possibly find other advertising avenues.