You can get unlocked HSDPA-USB-sticks for < € 90 from eBay Germany, e.g. from
this seller.
However you American folks should be aware, that there's no UMTS2100 coverage in the Americas, as networks there operate at 850, 1700 and 1900 MHz.
Proceeding on the assumption that the +423-tariffs also apply to new data SIM, since the
the PDF rate plan linked on the data-offer-page is headed "+423 rate plan", I noticed some discrepancy in the tariff information:
Whereas
the PDF rate plan lists Mauritius in zone 3 and so implies serivce for the +423 SIM, the
rate calculator doesn't give any rate for +423-SIMs for Mauritius.
Regarding Cap Verde
the PDF rate plan says it's in zone 3, where incoming calls cost € 0.19 and outgoing calls to zone 1 cost € 0.79. However the
rate calculator provides completeley different prices.
Also the SMS price differs - the
the PDF rate plan shows a worldwide price of € 0.39 and the rate calculator shows € 0.29.
Either UM haven't updated the database of their price calculator or different tariffs apply for the data card and the
corresponding PDF file has a wrong heading.
Anyway, I wonder why the data SIM works in more countries than the original +423 SIM, since both seem to originate from Mobilkom Liechtenstein.