[hexonexxon]

Better way to do this:

Go on localbitcoins and find people who mail cash for bitcoins, or find somebody on IRC to do it.

Sell them bitcoins, have them mail the cash to SDF for your payment. Now you avoid all the problems of physically mailing something from where you live. It's actually common for people to ask for single US bills in the mail too, for collecting.

I also would edit Torrc file to use semi trusted exit nodes from torservers.net so you aren't using a malicious exit node.

[sneak]

Then they get investigated, then give the investigators your contact info that they used to transact with you.

[hexonexxon]

Oh noes, then they get a Tor exit node where you contacted them on IRC or Bitcointalk forums, or a JonDonym free proxy you will never use again

[sneak]

It's also hard to get any significant amount of bitcoins anonymously in the first place to begin this process.

[BellsOnSunday]

Even easier, SDF accept bitcoins.