Ah IC. For Rotrex installation, you need to spend about 15-16k for new kit. The SC it self should cost you around 9K new, otherwise can try source a good used one which should be around rm3k maybe. Last time got a few who have installed but got some complication with the mapping (coz they sell the kit without remap and nobody back then knew how to remap the ECU!) hence some may experience knocking while others may got lucky and running more smoothly. But nowadays probably should be safer coz now already got a few shops who can remap the ECU. I have been thinking to install myself also once already got shops who can remap, but still not deciding since I'm actually also considering to sell mine!
This car has many variation in options since it's JDM, so things like push start, electric seats, ionizer, long LED interior lamp etc2 can vary too. So depends on what you need.
Speed limiter can be removed by 2 ways: either you install HKS VAC for Mark X (which I have), or you reflash the ECU. Back then when I got the car, not many shops can reflash so we use the HKS VAC but now quite a few can reflash already. APEXi RSM is not really recommended because it's actually not compatible and has a risk that it doesn't work in sync with the 6 speed gearbox. Got some people who have managed to get it working but its not easy job and need to be done by people who really knows how to wire and set it up. Other speed meters or speed removal module are also not compatible.
Wear & tear is very comparable to Camry and very reasonable for this type of car. Parts still quite easy to find and chop shop parts are also still abundant, and most parts are interchangeable with Lexus IS250/GS250/GS300. For common issues, really nothing much worth mentioning coz the car is really bullet proof. I barely spent anything to repair mine. Most of the money spent is on modifying/upgrading it rather than repairing which is great!