It is safe.. as long as you do your due diligence first.
A ) make sure when you go to buy it.. that they can at least prove it powers on. If its not attached to their account, it wont come up properly, etc.. but at least prove it gets power and is not toast.
B ) While there.. call into rogers.
Have them see if they are ABLE to add that boxe's serial number to your account. IF they can, you are set.
If NOT.. the unit is still tied to someones account.. either as a rental.. or even as an owned one, its still associated with their account. It needs to be REMOVED from their account, before you can add it to yours.
Is there somewhere here I can enter the serial number to check if it has been deactivated?
No there is not. Here are the steps you need to take to ensure a smooth purchase:
1. Call Rogers with the name of the seller and the STB number before purchase. This is to ensure that it's not a rental and is properly in Rogers system and is allowed by Rogers. Have the seller show the STB in operation if possible. This is especially important if it's a PVR because the iHDD could be bad. If they can't demo, then the price should reflect that.
2. Ensure the seller deactivates the STB or tells Rogers they're selling it so that you can then activate it.
3. You must call Rogers when you get the STB home to authorize it.
4. You must have the cable properly connected and a good signal to the STB for it to function/boot.
5. Sometimes another call by the seller is required after the buyer has the STB in his possession and is trying to activate it (due to Rogers Computer issues - there must be some difference between the "check" and the "activate" steps in Rogers' computer system)
6. If you are in Ontario, you cannot use a STB that is not a Rogers Ontario STB.
7. In the event you wish to incorporate the STB into a WHPVR setup, a truck roll (service call) will likely be required.
8. Sometimes we get questions about "moving" a STB from one subscriber to another without calling Rogers. This is against the Terms of Service with Rogers, they can find out (monitoring location), and both people could be in trouble with Rogers.
9. Note that there are some smaller Rogers areas in Ontario that utilize Motorola STBs. In those cases you need to purchase the correct Motorola STB(s) and it doesn't have to be a Rogers box, but beware of scam sellers. You cannot use SA/Cisco in a Motorola area, or vice versa.
10. If the seller is not a "customer in good standing" (bills all paid, etc.), then Rogers may have a lien against the STB, so calling Rogers before purchase, as discussed in point one, is very important.
OK, I think I get it now. You want to "rent-to-own" a box from Rogers. I don't believe they have this option any more. Only outright purchase*, or rental. Here's a link to pricing:
(Initially I thought your question was about purchasing a used box from another Rogers customer, which is what this thread is about)
* I'm not sure if Rogers sells boxes any more. If you wanted to purchase outright, you may need to purchase used from a Rogers customer in good standing on something like Kijiji (see post 13), or new from one of the few stores (2001 Audio Video?) that still handle Rogers boxes.