BIOs password dilemma

I purchased a ThinkPad this week on eBay, after months of searching I picked up a very good deal.

The bios are locked, and after making contact with the seller; they are willing to provide the password in 30 days time. Their logic is as follows; they have had issues in the past with customers bricking the laptop and then claiming refunds as eBay usually sides with the buyer.

I'm torn as I've really struck a bargain and the laptop works perfectly. So long as I have it in writing that they will provide the BIOs password, I should be protected in the event that they do not provide it, right? Will I still be able to open a dispute with eBay?

For reference, this is a business with a 100% rating and 1k+ sells.