I dont know your personal definition of pricey, I'll assume anything above $1000 is in that catagory.
Shorty headers and exhaust can bump the hp up between 15-25hp, the trick with the exhaust is to tune it to what rpm range you want the hp in. Larger exhaust will put it at hogher rpms, smaller at lower rpms.
Larger Supra injectors can add 5-10 hp.
Hotter plugs, wires, and coils can add 5-10hp.
Better airfilter and cleaning up the air intake pipe is good for 5-10hp.
Larger throttle body is good for 5-10hp.
All these items together might net 35-40hp at best.