The service Toshi provides is *not* expensive. In order to re-map an ECU it means he has to get (pay) someone to desolder the chip and insert a socket, then remap your chip on the dyno.
At $300 exchange this is CHEAP. Assume 1-2 hours to desolder and insert a socket, 2-3 hours in dyno and remapping + travel time. And then there's the followup service.
This means that he's charging around $90 / hour to completely change the tune of your engine. Try getting some else with tuning knowledge and see how much they charge! Once you've got the exchange ECU, re-tunes are fairly easy on the dyno and would presumably cost a lot less.
And, once you've had the tune, you may just be happy with your car for a lot longer, thus delaying the inevitable *MORE* mods!!
My 2c....