Toys R Us at Lakeside (both Retail Park and Shopping Centre stores) have the Official Darth Vader 4.5" figures with Coin Collector books for only 99p. All other figures are £4.99, reduced from £6.99.
I guess this is a Nationwide offer because the two stores I visited both had it. Unfortunately I did not find the bike I was looking for.
Offer does not appear to be online.
edit: Added pictures in post #7 below.