I have a mixed 105 10 speed groupset for sale.
It consists of 5600 levers (2x10) £35
1 short cage rear mech 5600 £20
1 medium cage rear mech 5701 £20
5600 brake caliper (front) and 5800 brake caliper (rear) £25
Shimano 10speed double chainset £15
11-28 cassette £15
11-32 cassette £20
These have all had a good few years use out of them but I'd say they're in decent condition still.
Prices above plus postage. (Let me know if any are widely out)
Edit: I'd like to keep the groupset as a whole if possible : £120 for the lot plus postage
I also have a nearly new 5800 11 speed RH shifter. - £40 posted
Also got a Giant 700c rim brake wheelset. Decent condition. £60 plus postage