You are assuming that keeping data in sync, running updates, paying for software licenses, etc. on two different devices come for free. A small laptop is not really a competitor - the cheap ones have really shitty screens, really shitty CPUs in them, no SSD, and crappy battery life.
The price for the hardware in a surface pro is in the ball-park. If your needs will fit the device (and I think you'd be surprised at just how many people in the business world are covered by this sort of device), then it is decent value. The vast majority of desktop machines sold to businesses run Word, Excel, Outlook and maybe project and a couple of legacy Windows apps from ~2000 or earlier. Maybe a terminal session.
An iPad has enough CPU power to cover that easily, but it isn't x86/x64 Windows so the apps won't run on it.
Comparing specs for most people is largely irrelevant now in terms of processor, expansion, GPU, etc. In the business world you're looking for a decent amount of memory, maybe SSD and a display that doesn't suck. Bases which the Surface Pro easily covers. Trading the additional portability benefits for some higher-on-paper spec or marginally cheaper machine (say $200-300, depreciated over 3-5 years - or a real world business cost of say 30c per day) is just not worth it.