£100 is about the minimum spend for decent binoculars.
Could also be used to kickstart a new interest, eg:
Shotg*n certificate application fee plus 2nd hand g*n cabinet (leaves no money for actual shotg*n, but you can buy used for £50 up)
Canoeing course - £100 should get you up to 2 star, maybe all or part way to 3 star.
If you're handy with wood, £175 will get you an unfinished hull from Apache canoes (special offer on Song of the Paddle)
Deer stalking course level 1 - £210
http://www.eskdalewildlife.com/training.html
A lot of good waterproof jackets around £100
A strike-a-light (for use with flint and charcloth) is a fine thing to have - £10 to £15. Available from Woodlore, but I have one by Mike Ameling which is excellent.
Victorinox Farmer off American ebay. £15
A bow (get advice first) £30 to £400
http://www.quicks.com/pdf/pdf12to27.pdf