In America, you should be able to find the Apex AD-600A at Circuit City for $169.99.  Their exact part number is: APX AD-600A, so have a friendly representative look that up in the computer.  Most stores are capable of searching the stock of other nearby stores, so if your favorite one doesn't have any in stock, ask them to check other area stores.

Heartland America has them in stock and available to be ordered through their online store.  They're $219, with a $20 rebate currently available (3/28/00), making them $199 + shipping.  Their site uses frames, so I can't bookmark the Apex itself, but if you go to their main webpage and search for 'Apex' you'll find it.  Part number WW22-96800.

Apparently, the AD-600A can also be purchased through a Canadian web store named FutureShop.  Do a keyword search on 'Apex' to find it.

It has been reported that Damark no longer has these units.
The AD-600A has also been found at Damark (800-827-6767) through a special "Great Deals" catalog.  Catalog number is B-20811-744733, and price is $179.99.  They are in stock as of 1/13/00.  A reader of this site ordered one and was quoted $13.99 for ground shipping.

The only contact info I currently have for Apex is that which was on the packing box:

Apex Digital, Inc
2919 East Philadelphia Street
Ontario, CA  91761
USA
909-930-1239 - Tel
909-673-0660 - Fax

The player itself is actually made by a company named VDDV (Visual Disc and Digital Video Corp.), located in China.  Their website can be found here.