There is a new "near virgin" ENTERPRISE-128 auction on the (hungarian) Vatera.
The computer is looking good, no scratch, including german keyboard, Basic cartridge, hungarian user's manual, original factory power supply and box, and the keyboard membran working very well. (as well the internal joy)

Start Price: 20000 Huf (61.5 GBP)
Auction finish: February 06. 2011

Here is the link.

I will see about it!

Found some current auctions:
Cyrus Chess cassette
German EP128 user manual
Arabic EP64

Rare version of the German EP128 on the Ebay. It is with a Enterprise 128K label not with the common ONE TWO EIGHT label.

think i will never be a proud owner 

You can try again: there is a another one.

I asked a Chinese seller seeking a card edge connector to the bus-extension hardware. The man offered me 5 pcs 2x34 pins edge connector for 4.2 dollar plus shipping.
If someone interests here is the link:
http://www.ebay.com/itm/140714761614

Why can't an EP cassette be bought that contains an original EP game we haven't known so far, with cool graphics and lots of levels?

eh, miért nem árulnak olyan ep kazettát, amin valami ismeretlen, marha jó grafikájú, sok pályás _eredeti EP_ játék van?