OK, just for the record:
DOCSIS = Cable TV internet (comes from cable provider)
ADSL = Telephone company internet (comes from telephone company)
So you're discussing two entirely different solutions. You were originally
discussing a DOCSIS cable modem, and now you're pricing an ADSL2+ solution
for ADSL. I would think that the monthly fee associated with those
two entirely different offerings, would be the factor of interest.
While getting a cheap modem is nice, in the long term, it's the
dollars/month that eventually adds up. So if cable was $50/mo and
ADSL was $25/mo, it wouldn't really matter whether the modem was
$30 or $100. You'd stand to save more, by pricing the monthly costs.
And sometimes, you don't discover how cheap they'll offer the
service, until you've talked to one of their "retention" boobs.
They've tried to make it every bit as bad as cell phones.
With regard to DLink, the consumer oriented companies of that sort,
offer downloadable manuals, so you should never be entirely in the
dark about their products. Some of the companies that make
modem/router products for ISPs, aren't nearly as generous
with the documentation. But DLink sells to consumers, so they
have a vested interest in having a usable interface on their
products.
On one web page, I can see the seller mixing up references to
DSL-2302B and DSL-2320B, so perhaps you'll find more info
by looking for the latter part number. And that one is $40
at Newegg.
http://www.dlink.com/products/?pid=554
ftp://ftp.dlink.com/Broadband/dsl2320B/Manual/dsl2320B_Manual_12.zip
http://images17.newegg.com/is/image/newegg/25-112-003-S03?$S640W$
http://images17.newegg.com/is/image/newegg/25-112-003-S02?$S640W$
Reviews on the 2320B are mixed.
http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16825112003
Paul