Expanded Clay in pots, trickle feeding through the pots, collecting in the tray and drained back to tank for recirculation. Uses a timer. This kit would be around $280

This is just a simple plastic crate fed by a trickle irrigation, and drains back to a tank. This one about $140

Tray is filled with clay, flooded for 15 minutes, then drained back to tank. Cycle repeats every two hours. This kit is $295
Tray size is 900mm x 900mm and also avail in 1100mm square and 2100x1100mm)

Satellite system - trickle feed, modular design. Easy! also starts from under $100. Most popular kit for indoors. Prices here and instructions here

close up on these roses in a satellite system