Machinedrum UW is the obvious alternative if you have one, & suites my needs almost perfectly.

The best alternative for your criteria is the Electrix Repeater if you can find one, although it is a 19" rack unit so not so small, but definitely cheaper than the OT.

Another thing I used was Ipad with loopy HD tempo controlled by my hardware with input running from Octatrack headphone out. Worked quite well.