You are reading it right, but it's not the 852nd Macintosh ever made. It' the 852nd made during the first week of 1984. Its pretty certain Apple was manufacturing production models as early as the first part of December 1983, if not earlier. And since the plant was manufacturing in expectation of a volume of around 500,000+ Macs per year, they were likely manufacturing somewhere in the neighborhood of 6,000-8,000 Macs/week (the plant could produce a completed unit every 27 seconds). So yours is like the 28,852nd Mac ever made.
As far as not starting, it could be relatively simple, or it could be major. Since the disk drive has power (the red LED), you know the problem is on the analogue board starting the video circuitry. In order to make it work, you'll need to get a torx screwdriver long enough to access the most recessed screws. Once inside, we can guide you what to look for, but you'll need to be comfortable using a soldering iron or, know someone who can help you. Considering the value, I would hate to start shipping it around to other folks who might offer to repair and risk loss or damage. However, with the money you saved you could buy a working analogue board off eBay and just swap it out. I believe I saw them recently for $79.
However, first things first ... it's possible that the voltage just needs to be adjusted, i.e. it's too low to "turn over the engine". That would be the best case scenario. But it's just as likely you need to replace a capacitor or two. Either way, you need to get 'er open and start reporting your findings.
Here's a document to get you started down the parth you're going to have to walk one day or another: http://68kmla.org/files/classicmac2.pdf