+1 most of the above. Except what is this second 'Miyata'?
AFAIK there's only the one, still in business after 120 years, though no longer exported to the US. A nice collection of their 80s-early 90s US catalogs is here:
www.miyatacatalogs.com
It's a mixte, with the split top tubes running directly to the rear, which is not necessarily a 'girl's bike' though some perceive it that way. Hard to tell exactly what model it is/was but as noted above the only mixte frame Miyata made above the entry-level 100/110 was the 210, which would have had a triple chainring, and this one is a double. There ought to be a name for this kind of cheap-o single-speed 'conversion' as it is very minimal, mainly taking things off, no value added but the chain. On the other hand that's an advantage if you want to turn it back into a geared bike.
If it's a late 80s 100/110 it's still a good if basic bike with cr-mo frame & perhaps fork and I think that's what the stickers are showing. Below that Miyata had a line of bikes with names like 'Nimbus' which are heavier hi-ten steel, definitely lower-end.
For that kind of money you should be able to find a good and intact mid-80s road bike for a very reasonable price. There are lots still out there particularly the Japanese makes like Miyata, Shogun, Centurion, Fuji.
First step should be figuring out what size is right for you. Browsing this forum should provide lots and lots of useful info. But be careful...a year ago I didn't know a 'mixte' from a 'fixie' and now my whole family have road bikes, I have two for myself, and a serious and time-consuming new hobby.
Its kind of fun though!
btw: all our bikes are Japanese, one late 70s, the rest 80s, all but the latest were under $100 on CL.