$250 sounds like s 'swap out' deal, probably transplanting the existing drivers to a remanufactured housing.
Make sure the channel isn't clogged with wax. My sensaphonics sleeves for my now-sold Shures came with a little wire tool for digging it out. Shure considered filter replacement a send-it-in process unlike the Etymotics which are supplied with a filter changing tool. If they're charging $250 just to change filters, that's a ripoff IMO. I'd ask them for specifics on what your $250 is buying you. For $100 more than that, you can buy a brand new pair of TOTL Etymotic ER4 SR's or XR's which are user- serviceable to a large extent.
I have soured on the 'value proposition' of customs. They're really expensive... None seem to deliver the level of isolation promised (universal fit provides just as good isolation once you find ones that seal and fit well... and worst of all, your ears internal shape actually changes subtly over time*, potentially ruining your $$$ investment; they may only be effective for 2-4 years. The best universal fit tips for me have turned out to be Spin Fit CP240M dual flange, $10 a pair from Amazon. They do just as good a job as customs for me and are a lot easier to clean than memory foam tips and last longer. Theoretically, triple flange is better... theoretically. In practice I have found that what fits best, isolates best, which in my particular ears are the Spin-Fit dual flanges. With all these YMMV of course.
*I was told this by the audiologist who did my impressions for my Shures.
