Thanks to Paul, I just found out about the ShouYu SY-X5: a new analog DSP-based shortwave radio with built-in MP3 player. Like the Degen DE321, DE32, Kchibo KK-9803 and the recently released Tecsun R-2010D, the SY-X5 has a mechanical tuning mechanism powered by a Silicon Labs DSP chip.
I just purchased the ShouYu SY-X5 from this seller on eBay. The total cost was $27 US including shipping from Hong Kong. There are other sellers offering the SY-X5 on eBay, but their prices are almost double (with shipping from the US).
At a low price of $27 US, my expectations will be adjusted accordingly. My hopes are somewhat higher for the Tecsun R-2010D as Tecsun tends to do a better implementation of DSP chips than their competitors. Since I’ll be receiving both units within days of each other–and I still have the DE321 and DE32–I will certainly compare them.