the price is an outrage ! do a search on ebay to find out how much the parts are. then if you don't fancy doing it yourself, have a ring round some local towbar fitting companies, some will come to you if you wish. I think you'll find you can get it quite a lot cheaper.
Although mine is a freelander 1, the towbar cost £85 from ebay and took and hour and a half to fit including the single electrics.
If you're only towing a boat and never intend towing a caravan, just go for the single electrics to power lights and indicators on trailer. No point having the split charge doubles if your not towing a caravan.
this one may be more suitable, need to ring them really:
this does gloss over the problem of it being fitted with the sports bumper, maybe ring just tow and ask. worst case you're going to have to cut the oh so pretty bumper yourself. This was just the first search, so if you go through them all, you might even find a kit to suit the bumper.