Scam alert!
I'm dark net proficient as well and assure you it is not hard to use nor worth paying "a lot" of money for. At best you're getting massively ripped off. At worst it's a scam (more likely)
You don't really need a virtual machine for ctb purposes. It's not worth law enforcement's resources to go after personal buyers. Even if they did they would have to create a case profile against you which would likely require you to place a substantial number of orders.
If you're just placing an order or two then tor + a vpn is sufficient.
As another user said use monero rather than Bitcoin.
I use whonix on a virtual machine since I've been ordering drugs since 2017. You don't need to unless you plan to place multiple orders or a large quantity.
If you have any questions let me know. Free of charge because seriously it's not fucking rocket science.
They have experience with secure govt installations
This absolutely sounds like the type of bullshit scammers say.
How are "govt installations" (installations of what?) remotely relevant to figuring out the dark net? They're feeding you horseshit.
You don't need a degree in quantum computing. You could teach a monkey to use the dark net.
You would need to wash BTC
Probably not if they're buying in personal amounts. Law enforcement isn't going to drop the ridiculously high amount of time, cash, and resources to trace the block chain only to de-anonymize someone who bought a bar or two of Xanax, for example.
They'll only spend that kind of energy on the big fish.
I recommend monero entirely on the principle of it being totally anonymous/impossible to trace.