Over the generations, as we unlearn the ability to write in more coherent words and sentences, misspelt words like the one in this eBay listing will become more common.
There could be several reasons for the incorrect spelling.
I have no doubt that it was not deliberate nor intentional. There is the unlikely possibility that the writer did not know how to spell M-A-T-E-R-I-A-L , after all the letters composing the word are all there. The pronunciation alone would guide the spelling of the word correctly, given the ability to pronounce it.
A common typing error is to type letters that are situated next to the correct ones on the keyboard. The writer (typist) would probably not pick up on this mistake because all the keys were pressed. So in the writer’s mind, the word has been typed out.
In this case, the sequence of the keys being pressed on the keyboard resulted in the poorly written English mistake. “A” should not precede “I” but in the rush of typing the word it did.
In years gone by, the skill of typing was to some degree specialised. It was taught, it was acquired through practice and practised by those employed to do so. Think about it, the wheels of this literary language were turned by people professionally qualified. Typing was a skill mostly practised in the workplace. The workplace was a structured environment, there was order, there was a hierarchy. Each member of the organised workforce has his or her role and measured on the ability to carry out that role. Kids did not have to type, people not qualified to operate a typewriter would not have had this problem. They probably had a secretary or typist to create typed documents.
Today we have a flat corporate structure, fewer supporting admin staff, admin staff and colleagues not educated in the right way, people read fewer books, books are published with mistakes, proofreading is seen as more of a luxury than necessity… it just goes on. People just aren’t speaking proper.