JP1 is very cheap and incredibly flexible and vastly more powerful than harmony. A typical JP1 remote is $15, and the programming cable is $18-$30 (or less if you make your own). You can make all your one button macros behave exactly like activities. All you'll be missing is the LCD for additional functions (those will have to go on other hard buttons). My children have never had any trouble with my JP1 remotes from the time they were toddlers. See the links in my sig for more info.
If you want something like harmony, just get an older model or refurb. Most of those do 12-15 devices and are in your budget (see the chart in my sig). JP1 remotes do unlimited devices thanks to device multiplexing.
PM me if you want a harmony 360 cheap (almost identical to the 550).
To give you an idea of the capabilities of JP1 versus harmony, harmony has a programming wizard, help function and an LCD for additional activities and functions. These are big advantages over cheaper remotes and ones that JP1 lacks. However, for sheer programming capability, JP1 wins hands down. You have complete control over the content of macros, can add most functions without learning, easily add pronto hex, analyze IR signals and create any custom protocol for any device, have macros call other macros and even recurse themselves, assign up to 5 functions per button (short press, long press, double press, shifted and double shifted), multiplex devices for unlimited devices, interrupt macros with a button press, custom device state tracking, rudimentary if...then...else via toadtog bits, device specific macros over 5 steps.
Also JP1 is not dependent on a web server for programming. You keep all your config files local and can have as many as you like. Updates take about 3 seconds versus a few minutes with harmony. And unlike harmony, the software has a graphical interface where you can drag and drop functions onto an actual image of your remote. Harmony's new web-based software has something similar but at the expense of losing many other capabilities. And since JP1 is built by and for users, support is fast and free forever. If you ask for a new feature in the software, you'll likely get it very quickly.