Ebay is fine. BMW cut corners putting this X in production. I recently had both fronts CV boots replaced. 2000 4.4 X5. You install yourself? If so good. If not, hope you have aftermarket warranty for this and future service parts. Could get costly. Common X5 problems are:

CV Boots
Radiator Hoses
Control Arms
Window Regulators
Final Stage Resistor
Cluster Display