Well.. lets see:
Bintel, red dot finder, Adjustable Brightness, Four Reticle Patterns, All- Metal Construction, $89 (from catalogue)
ebay,
http://cgi.ebay.com.au/Electro-Red-a...item27b10dc590
$33.99, delivered to your door.
Same thing... OK, bintel one has a stand (dovetail).... So the stand (piece of aluminium, more or less) is worth $45 ?
Some time ago they had Orion branded (all plastic) Red Dot finder for ~$80 (it is $49 now).. and I paid for the same thing on ebay (no brand) $15 + couple of bucks for p&h.
So, the reasons to go to ebay are obvious..
Of course, if I see questar offered for $50, and knowing that it was sold for ~U$2000 back in '80-ies) and the latest ebay offer is $4500 (quite reasonable).... something must be wrong then with the cheap offer :-)