Last year I called Coinbase and spoke to a nice lady. Being a computer Luddite, I could not figure out how to purchase Bitcoin online, and it was around $3500 at the time. She said send a check for a minimum of $5000, and they would purchase the Bitcoin for me. On Sept 26th I sent a Cashiers' check for $9500 and got a signed USPS receipt for the envelope, so I know they did receive it. Bitcoin was around $6000 by then. After a few days I tried to call and only got a phone tree. Left a message but no response. I then tried to open a case, told them the above, and they responded saying they had to research it. They then closed the case without responding to me. I did the same thing one more time, with the same results, they never responded that they ever found my check. By Christmastime, I gave up and got the bank to put a stop payment on the check, which was quite a process in itself. They never deposited it or credited my account, and by then Bitcoin was over $9000. I strongly suggest you do not deal with these people.
Jeff
Gardnerville NV