I switched way back in the late 80's. I bought 2 CD's in 1988 and I knew after the first one I could never pay money for a cassette again.
I too had probably 1,000 cassettes, but sold em all and slowly replaced em on CD.
An interesting note, the LAST audio tape manufacturer in the US shut down last month according to Billboard magazine, and they did so without notice. It's causing quite an uproar in the industry.
I still keep a cassette player on hand even now though, because there's so many great albums that were never put on CD, I like to buy the cassette off ebay, run it through cool-edit, clean up the hiss & make a CD out of it. So I imagine I'll still have use for the good old cassette for another decade or so!