Between my kids and me, I go through a lot of scrapers during the season. To me, the worst chore is scraping, especially with a dull scraper. I'd much rather throw a dull $4.00 scraper in the trash then try to get every last bit of use out of it, but this is starting to add up. Are sharpeners effective and worth it? Can they put a "good as new" edge on the scraper? My fear is that they get so gunked up with wax or don't restore a good enough edge, that I won't want to bother with it. Tell me your experience.
Get a carbon steel scraper. Save the plastic for the edges only. Use something to hold the scraper vertical as you use sand paper to sharpen it once in a while on a known FLAT surface. I have used the same carbon steel for years.