How much did it costed?

The Conversation tweeted about an article way back in 2018, when things like the World Cup still happened, and included the phrase could have costed (it's also in the article itself):

Watching the #WorldCup during working hours could have costed as much as US$10.4 billion in lost production time (in 2010).

But there are multiple ways employers can make up for this by embracing the tournament: https://t.co/qyewW8oxVQ pic.twitter.com/apqvOr9zgF

— The Conversation (@ConversationUK) June 12, 2018

In Standard English that would be could have cost – cost is irregular and has cost as its past participle as well as the bare form. In fact, costed isn't even the simple past tense of this version of the verb, as that's also cost:

It costs	Present
It cost	Past
It has cost	Perfect

 and so on. 

I say 'this version of the verb' because there's another version of cost that does have costed as the past tense: the one that means 'estimate the price of' rather than 'have a price of', as in We costed the new plans and decided that they were not viable. So there is this form costed that exists, and that you might have heard just as recently as the form cost, and you might reach for that when you're looking for the relevant form to follow the perfect auxiliary have. And then that makes it nice and similar to all the other regular verbs like could have washed, could have dusted, could have wasted, etc. 

I predicted that this mistake would be much less likely to occur with did instead of could have. While could have requires the past participle (actually it's have that requires it, so you'd also get it has lasted us ten years, and by extension possible it has costed us a fortune), did doesn't – it requires the bare form of the verb: Did it last long? rather than Did it lasted long? and so presumably you would expect Did it cost a lot rather than Did it costed a lot? 

Well, never make predictions about what kind of variation people will produce. I'll leave the actual numbers to someone else, but a google search for "did it costed" brings up results, and not just people asking if it's correct to say that (though they're the top hits). There are also examples where it's used as the simple past form, as in I wonder how much that upgrade costed. 

English, amirite?