Not yet and i will never try to bought on deepweb. Like others im afraid and i dont have enough knowledge on deepweb. I'm not into drugs or any illegal thing. Why go to deepweb if you only want to buy phone or something that can be found in a mall. Just convert your btc into fiat and go to mall rather that buying something using btc in deepweb.
The exact steps for Deepweb has become one of the network that is dangerous and scary for us. Deepweb is central to the transaction is illegal and is strictly prohibited by all countries. Even Deep has now overseen by the FBI and that can negatively impact if we Transact in Deepweb, although we Transact legal stuff
I see you are afraid of FBI, here are the steps to follow and to not give a damn about FBI or any other agency who wants to spy the TOR network, there have been a very few successful attacks from FBI like when they raided Silk Road and another website which I don't remember (both big mistakes of the users who put their servers in the USA)
1. Using TOR and Windows, especially Windows 10 which is more a spying tool than an OS is a really really bad combination.
2. Keep your OS up to date ALWAYS(very important as one attack of FBI hitted an exploit of an version not up to date of Firefox) and always put privacy and security settings to the highest.
3. Don't torrent over TOR or open .doc or .pdf files , very dangerous opening this online.
4. Don't use add ons like Flash or alike, they have a funny habit or revealing your true IP
5. Javascript should be always disabled. Keeping privacy and security settings to the highest disables it by default on all sites.
6. When using TOR do not open other browsers simultaneously as you risk to get your IP revealed.
7. Never put any identifying info of your self which u use in the clear web. TOR should be your double identity no one should know about.
Now FBI will have some big big trouble identifying you ,whatever you are doing in the deep web.
it's very easy to enter in deepweb try to do some research or join in deep web facebook groups it can help you and i suggest before you enter deepweb try close remove your webcam, microphone because it will automatically run when you enter the deepweb and the hackers will blackmai you.