gpx250 carb sliders

I've recently brought a 92 gpx250r and after much stuffing around with the carbs have come to realize that my carb sliders are worn and leaking air and that is why the revs jump to 4500 as soon as I touch the excelerator, anyways I rang pro moto and was quoted $260 each slider and was wondering if anyone knew if there was a cheaper slider that fit or another option

get some carbs from another GPX or ZZR250 mate. These should be way cheaper than >$500 !!