We had previously allowed for guests (non-registered users) to make purchases from the classified section. Unfortunately we needed to turn this feature off.
Too many people were providing bogus email address (or email addresses they neglected to check) when making purchases. The sellers would try to reach out the the buyers and fail.
Now, all buyers are required to verify an email address. However, only registered users can do so. If you are a registered user and you have not yet verified your email address, an email will be sent to you when you try to make a purchase. You must be logged in and then you must click on the link in the email to verify your email address. This will flag your account as a valid buyer.
People who have already successfully made purchases are grandfathered. Their accounts have ben pre-flagged to allow them to make new purchases. You only need to go through the email verification process if you have never made a TroveStar purchase.