There are more elite ways to do btc transfers but I know most of you meatheads aren't even good with computers..I kid... lol
Setup a coinbase account to transfer money to securely and easily. Very easy and reputable but also trying to be THE mainstream and plays ball with LE and heavily audits activity. My roommate from law school works in their auditing dept. (formerly a Goldman employee in auditing). Circle is OK too, but coinbase is slightly better (higher limits).
You should all know Bitcoin (btc) is not truly anonymous. Especially with services like coinbase. Distance your bank or cc accounts and name from any btc transfer used in purchase. Transfer portions of btc to a separate blockchain wallet. You will purchase with this blockchain wallet, not coinbase. When you buy from coinbase or circle, they have all your info so its best to send it to blockchain or another less mainstream wallet focused more on privacy to try to obfuscate the purchase more. Plus it will help keep from getting your coinbase acct shut down if activity does get audited. It's like washing your coins to a degree but this is still not flawless, just more safe. Blockchain has no limits on the amount you can send in a day other than how much btc you have.
I recommend this approach as a minimum level of security. If you want even more secure, complex ways to detach yourself from the btc origination and transfer, research it.
Sources like pharmacom now do btc transactions. Safer for all parties involved if done right. If you just get a coinbase account and start buying illegal shit with it I would actually say your exposure and risk is higher than a good old fashioned WD/MG transfer that's harder to audit due to sheer volume. You've been informed...