In the early 1990s I had a Yamaha PSR-500 keyboard that I bought initially to record tracks with its built-in five-track recorder. Eventually I moved up to the Master Tracks Pro MIDI-based program and used it as a controller. After recording a song, I would link then trigger the sounds via my MIDI interface and record the sounds as a stereo (or sometimes mono) track on my Tascam Portastudio cassette recorder.
I really loved that keyboard. It had two fairly high-quality stereo speakers that had some umph to them. The piano sound was much better than the sound of its competitor, Casio, which started the portable keyboard industry. (Casio's portable keyboards seem to be improving recently).
Eventually, I upgraded to a 76-key Yamaha DGX-202 keyboard and gave my PSR-500 to a singer friend. After only using the DGX for a matter of months, another musician friend presented me with an unbelievable deal on his Roland XP-80. So I lent (gave?) my new DGX to my musically talented cousin.
But ever since, I have missed having a portable keyboard. So I sold some gear on eBay and with the proceeds bought a refurbished Yamaha YPT-310 from a popular online retailer. Because technically it was used, there was no sales tax, and the shipping was free. My total cost was just $120 and what a good purchase it was!
