I've just bought a half lamb box here in Jersey. I can't help with butchering costs but I can tell you what they offered for the money
I had 2 options. Both are texel or texel cross sheep and are grass fed (I do not know if any extra feed was used)
A) £9.50/kg
2 x Half legs of lamb
1x Whole shoulder on the bone
1 x Rack (french trim)
Chump chops
Loin chops
B) £90 (approx. 8-10kg).
1x whole shoulder,
2x 1/2 legs,
loin chops,
double cutlets,
leg steaks or diced lamb,
1x shoulder fillet,
boned and rolled breast,
neck for stewing and
bones to make stock
This one also specified that its 10 day dry aged lamb
Neither offer the offal with it but I presume you could ask for it if you wanted it?