Nice list you've put together. I noticed that a couple items on your excel document were priced higher than on the link you gave, so a couple of items may have dropped in price. Your water bottle was one of the items I think.
Have you already started to buy some of this kit? The reason I ask is because I was thinking about postage. You have sourced your list from a
lot of different websites and paying the postage for individual items could add a
lot onto your final cost. I mean some sites are reasonable with postage, but some arent and will expect to charge you next to a fiva regardless of the weight of the item. ie. you wouldnt want to buy some £2.50 cutting wire online and pay more than that for postage would you?
Its a brilliant list you've gathered, I recommended reviewing each item and think what features is it about this item that makes you want it. Knowing its functionality & features you like you can then also visit local surplus or camping stores in your town and look for deals. If you find yourself a deal locally on a sleep-bag for example and it has the features you require you may just save yourself 4 or 5 pound postage. Getting smaller items locally would be better too, eg. wire-saw, ziploc bags, gaffa tape, paracord, hex-fuel etc. you could pickup from local stores and wouldnt have to pay any postage for each and every item, saving you a lot in my eyes. Online shopping will find you better competition and discount on larger items and it would also make it useful to buy some of the larger items you need together on the same website to share the postage fees. I have recently been looking for a lot of new kit (see thread:
http://www.bushcraftuk.com/community/showthread.php?t=15742) I have used the net as a superb resource to shop around, find kit with the features I want, checkout competitive prices, and then I know what sorta thing I want for the price I want, so when im in local towns generally for other reasons I just pop into surplus stores and checkout their deals, I've picked up a lot of stuff like that and have saved money
Just an idea. Good luck on the search and let me know if you have already started buying.