What kind of $$$ do you think I could get for a slightly souped up honda 13?

It's recently had the governor removed. Installed a bigger carb jet, stronger valve springs; gas tank removed and pulse pump added with fitting for external fuel tank. I swapped an almost new oem replacement muffler for a header pipe and screw on mini muffler. Custom air filter and oil breather filter. Runs Great! How much $$$ should I be looking at?

Maybe try a go kart forum? might be a bigger market for modded small engines.