Reddit mentions of K2 Skate Midtown Inline Skates, Blue, 7.5

> what are the pros and cons of hard boots vs. soft boots?

"The Difference Between Hard and Soft Rollerblade Boots" by Skates.Org

The short version:
-- Hard boot skates are generally more durable and generally offer better support than soft boot skates, but are generally substantially heavier and generally more expensive than a comparable soft boot skate.
-- Soft boot skates are generally lighter, generally more comfort-oriented, and generally less expensive than hard boot skates, but are generally less durable and generally not as supportive as hard boot skates.
-- Hybrid boots take the best aspects of both hard and soft boots (and may add other bells-and-whistles, like asymmetric lacing), but are usually very expensive (easily in the high-three-digit or even low-four-digit range) and geared toward skilled fitness skaters, speed skaters, and marathon skaters (that is, they are generally not "beginner friendly").

The Rollerblade RB80 and the Rollerblade Fusion X3 would be typical hard boot "urban skates" skates that would fit your budget, and the K2 Midtown and K2 Broadway are typical soft boot urban skates - "urban skates" being the type that are designed for skating through a city or campus area; see here and here).
Additionally, all four of those have the ability to replace the frames (something that most recreational and fitness skates within your stated budget lack), so that one can dramatically change what the skate is capable of, or replace the frames if they are damaged, and (unlike the Seba FRX80) should come with a heel brake assembly either already-attached, or unattached in the box.
(The IW specs page for the FRX80 states, "No Brake Included - Sold Separate", so one would need to purchase the compatible brake assembly separately from the skate itself.)