There is also Outlaw Audio's ICBM. While primarily designed for bass management for multi-channel audio (SACD, DVD-A), it can also be used as a 2-channel crossover. It has continuously-variable crossovers from 40HZ-up, and either maintains stereo bass output or combines low-level signals into a mono LFE-out.
New it is only $249, and I think there are some used ones listed on A'gon for under $200.
New it is only $249, and I think there are some used ones listed on A'gon for under $200.