BTBR set up is the best part of £300. Sounds dear but he does do a great job of the wiring. Having done the job myself, I can vouch that it is a pain in the arse job and BTBR is justified in charging what he does. If you have the time though you can save a good amount of cash.
Not that I need to, but just to clarify my costs.
I charge £115 labour/parts to fit a custom made loom to the bike. The 'cost' of the parts is £25 alone.
Breaking that down even further, it takes 3 hours on the day to fit to the bike.
Prior to that it takes about an hour in advance of the day to wire the lights up with the custom made leads.
On top of that I have to make the loom, and this takes roughly 2 hours.
On the day you are supplied with copious amounts of tea or coffee, plus the now lengendry Mrs BTBR sausage sandwich.

Not included in the cost of the lights I know, but all part of the service.
Now if you think that my labour cost is expensive, well I have a receipt here from a BMW dealer (who will remain nameless), and the cost on it is £362 inc VAT, just to fit and connect up one set of extra lights into the main beam circuit.
The lights that I supply are Hella FF50 & Micro DEs, these will cost you £118.36 and that includes the carriage costs to get them shipped directly to me.
Then we have the cost of the lightbar and Autoswitch (1150) or PIAA switch (1200) So allow another £100 for those items.
This gives a grand total of £333.36