Looks like the fine print doesn't exclude coverage for units purchased on Ebay:
For less than $200 it might be worth a shot. And there are all kinds of things that could be called in as defects on that unit!
2. Eligibility
This Plan is available to new and existing DISH Network customers who purchase or lease DISH Network hardware products. The Plan monthly fee of $5.99 includes coverage for up to 6 receivers. The Plan is only extended to the original customer who enrolled in the Plan and is non-transferable. You represent and warrant that the hardware for which you are seeking coverage are in proper operating condition at the start of the warranty coverage and that your DISH Network account is current and in good standing. No activation fee is required for customers purchasing the Plan for the first time.
3.What is Covered
The Plan covers repair or replacement of defects in materials or workmanship for DISH Network Direct Broadcast Satellite ("DBS") video hardware, remote controls, antennae, or switches that were i) purchased or leased by You, (ii) that are activated on your DISH Network programming account, and (iii) that are installed at your residential location (“Covered Product”). Your residence must be in an area where you can legally receive DBS transmissions from a DISH Network satellite.
For less than $200 it might be worth a shot. And there are all kinds of things that could be called in as defects on that unit!