TRD roots supercharger
Well, that prooves the point doesn´t it. Even that sets you back 300€ plus hassle/pro to install and most likely set it up at €s per hour; say 500€
If you mean the piggy back It’s easy. They usually come with a harness and you simply plug it in, no pro needed. The old Hass kit came with a tune that was made for it. The E-manage is old technology but it did work well. As for the whole kit that was installed by most enthusiasts over a weekend and was fairly easy because there was a good amount of support.
These days the newer kits use the AEM EMS which hooks up to the stock ecu and the kit manufacturers give you a base tune. Although it is recommended to have the tune checked it can be road tuned.