Unless dealing with a licensed motherboard provider (authorized service center or main sales office), be cautious about purchases from other sources. With eBay, look for feedback counts that are high and good. And also look for a warranty or "no DOA" statement. While most eBay retailers are very honest, there are a few that are not.
Go with the model number and service tag number on the case of your laptop for an exact replacement. other model motherboards may not fit physically, or have the same features as the original one.
With most computer and laptop models, there is a limit as to replacement parts. Many times, after a few years, only the 'used' market is a source.
F@H.. to solve mankind's maladies.. in our lifetimes!