I am typing this on a Thinkpad whose battery came from eBay. I have bought more than a dozen batteries off eBay for myself and others. One was bad and was replaced by the seller. The replacement is still in use after a year. So I guess you could say my experience is a good one.

On eBay you can either buy IBM brand batteries, or you can buy generic batteries. If buying a generic battery, I always buy from someone who gives a warranty, has a 99% rating, and has thousands of successful sales.

I just did an eBay search. Looking quickly, you can get a genuine "IBM LENOVO THINKPAD X60 X61 8 CELL BATTERY 40Y7003" for $99.99 including shipping. and a "NW Laptop Battery for IBM Thinkpad 40Y7003 X60 X60S X61" for $48.90 + 7.90 shipping. from some place that has a 99.7% rating on 17,071 sales. The latter gives a 6 months warranty, which covers the most common complaint - a new battery that won't take a charge.

I wouldn't personally buy an eBay battery direct from Hong Kong because it would be so time consuming and expensive to return it under warranty.

As to what you should do, you should go with the choice that makes you most comfortable.