The short answer: when used as a noun, the "price" is the amount charged for something, and the "cost" is the amount paid for something.
When a person is discussing buying something at retail, the most common noun used for the amount charged by the seller is "price."
I wanted to buy a white cotton jumpsuit, but the price was too high, so I didn't.
When used as a noun, "cost" refers specifically to the amount paid by someone for something. It is most often used in an accounting or business context.
Our cost per item is three dollars and our gross revenue per item is sixty dollars. That's a fifty-seven dollar profit on each jumpsuit sold!
It is not exactly wrong to use "cost" as a noun in the same way you would "price":
I wanted to buy a white cotton jumpsuit, but the cost was too high.
However, this is not as idiomatic, at least in American English; it sounds a bit melodramatic. You would be more likely to use "cost" as a noun where it is understood that you are discussing the impact on your finances, rather than the amount the store asked for the item:
Sure, it was expensive, but the cost isn't what's important: it's how the jumpsuit makes you feel.
Confusingly, you can use "cost" as a verb to describe the amount charged for an item:
That's a lovely jumpsuit; how much does it cost?
"Price" as a verb is used only for the act of setting a price:
Why would you price these jumpsuits so high? We poor students need jumpsuits, too!
Formally, we use accuse with an act—we assert that somebody did something reprehensible:
Mary accuses John of failing to lock the door.
But we use blame with the outcome—we assert somebody's responsibility for the undesirable result:
Mary blames John for the robbery. OR
Mary blames the robbery on John.
Informally, however, these distinctions often blur. For instance, if the robbery has already been mentioned, blame may very easily take a for clause which explains why the target is blamed:
Mary's house has been robbed. Mary blames John, for failing [=because he failed] to lock the door.
And accuse may take a complement which expresses a state rather than an act:
Mary accuses John of being responsible for the robbery.
Best Answer
Yes. "Bad English" is an example of "Bad English". "Poor English" is an example of Proper English.
"Bad English" is grammatically correct, and perfectly understandable. But in contexts where both "bad" and "poor" are appropriate (and have the same meaning), "bad" is informal, whereas "poor" is formal. Most native English speakers learn the word "bad" before they learn the word "poor".
For example, a school teacher might talk about a student who has "poor English language skills"; she might want her students to "speak English well". (Notice that "well" is an adverb, which modifies "speak".)
The student might just care about whether he has "good English" or "bad English". If he just started learning, then he probably knows the word "bad", but he might not know the word "poor". So people with "bad English" are less likely to say things like "poor English".
By the way, there are many situations where "bad" and "poor" are not synonyms. For example, Michael Jackson sang "I'm bad." But he had lots of money, so he was not "poor" financially. He was also a very good poet and singer, so he was not a "poor" artist.