Is it worth waiting for Windows 10 before replacing a PC?

Michael wants to replace his five-year-old laptop and wonders whether to buy now or wait in the hope of getting something cheaper

I want to buy a new laptop for general purpose family use. Should the launch of Windows 10 affect whether I buy now or wait in the hope that vendors sell off older models cheaply? Given that it might be a free upgrade, I'm wondering if this changes what normally happens before a large upgrade.

I'm currently using Windows 7 on a five-year-old Toshiba Satellite L500-1WG. Based on how I use my laptop, I think I'd find Windows 8.1 hard to get on with. Michael