Yeah, watch the movie, it is awesome (as it's song says). But seriously the film is great and it puts the figures in a whole new light. The other part of collecting the mini figs are the extras you end up with. My daughter spends hours switching them all about and creating all new figures so the more variety the better.
I think after the Simpsons they are back to the standard CMF's with a fresh wave due around the end of the summer.
I would advocate you take a good look at the SW Lego sets, maybe avoid the mass produced stuff and focus on their collectors sets. The current Red 5 x-wing, the super star destroyer, the upcoming sand crawler and the rumoured upcoming slave 1. Hell, there is even talk of Disney pushing for a re-release of the 5000 pieces falcon that came out in 2007. Also the current R2 droid build. And if you step away from SW some of The Lord of the Rings sets are great, The Tower of Othanac is something else. Sorry I do love my Lego... I already have a slot booked on the 28th to run out the office to the Stratford store to buy the sand crawler on day of release
As for £5499 for a full set of figures

wishful thinking. A few of the early series figures do go for £20-£30, the series 1 zombie and clown are silly money, but most settle around the £5-£8 mark. There are a few exceptions when Lego decided to only include 2 of certain figures in a box but overall I would say an average of £10 per figure of which there are 192 would put a full set around £2k