OK, I've done more research....
Apologies for my rant about op-amps before

; sometimes I get frustrated at what can be charged for really simple electronics

and rave on a bit....
If the Beringher you have is
the MX882 Ultralink-Pro then it will offer unbalanced -10 - balanced +4 conversion over six channels. If you drop the levels down on the output then you'd be able to feed this into the -10, but its not really ideal; you may get noise (it is a Behringer after all

).
The problem is that you're probably more in need of +4 to -10 (desk to recorder) than the other way around - you can just tweak the channel gain to go the other way.
If you can get the Tascam for a couple of hundred then you're probably doing quite well. I checked some equipment sites and found these other options:
Aphex 124A two channels bi-directional (you'd need four) - being Aphex it's probably not cheap, but they make nice stuff.
Sonifex RB-LU4, eight channels, balanced-unbalanced about 270 pounds
Gaines 248 eight channels balanced-unbalanced for US$449 (I love those large, detailed pics of the back of equipment!

)
Radio Design Labs RU-LA2D two channel bi-directional.
Quest AB2C Australian 2 channel bi-directional.
And there's a heap more. I'd still recommend that if you know someone who's into electronics then it would be worth talking to them about making one up!
Cya
Andrew