Actually, I paid about 300 USD for it (online), chiller prices vary wildly here, even depending on which online shop you use.
I've only had it for about two weeks. The weather has cooled down a bit the last week, so its just idling now. The first week I ran it the weather was much warmer, with the room temperature rarely dropping below 28-30 degrees. Even though I tried to set it to 25 degrees, it didn't manage to go below about 26.5 degrees, and it used several hours to get there.
I'll try and contact the manufacturer directly, they seem to have a 1 year warranty. What kind of chilling speed should I reasonably expect? For instance, how many degrees can I expect it to cool per hour. As you said, the chiller should be more than capable of chilling my tank on paper, and I bought their biggest model with the hope that it would result in the compressor not kicking in so often. Also, I hope to upgrade my lightning to MH
btw., mistake in myinfo), which seems impossible with the current performance.