They will try their best to convince you the solution can be delivered on time by some "expert". Do not believe it.
I paid $300 and get a OVERDUE solution with 30% correctness.
I have an assignment passed due and got 0 directly because they didn't deliver the solution on time. Although I have asked so many times if they can handle it and they said definitely. They won't let you know until the last hour.
Even after that I paid the money and want to get the correct answer. However, after I paid $300 they sent me a Poor Poor solution, which only gets 30 out of 100 score by running the test cases.