I think the bike was simply reduced.
Perfect city bike ! vintage Raleigh Sports 3 speed cruiser - 23" | road | City of Toronto | Kijiji

A 23 is still pretty tall for 5'7. You could probably fit onto the seat, but you won't have much clearance when on the top tube. Any chance you have a few more inches growth? Or like some of us, looking forward to shrinkage

Anyway, that looks like it is in pretty good shape for a pretty old bike. Around here, there are lots of old 3 speeds (requiring restoration) for less than $100. But the paint on that one looks fairly good. It may still need a complete grease job if not done.

You have to determine your goals. An old 3 speed would be great for cruising a couple of miles around the city. It will get old quickly if you head out to the open road for 10+ mile rides.

I'm pretty mixed on "classic" vs "new" for a starter bike.

Lots of good classics for cheap. But, there are also quite a few bikes, say around 5 years old that can be picked up for a good price with many of the new advancements such as brifters, 1 1/8" fork/stem, more gears, etc.