I have an original Sizzix machine from before the Big Shot came out. I bought it when my kids were at playgroup and I was running mums and toddlers - I used to buy myself dies from ebay as a treat, and it was absolutely excellent for producing piles of paper flowers, or Christmas trees, or anything really - you can have a quick themed craft activity for the price of a few sheets of coloured A4 paper and five minutes work.
These days I mostly use it for making my own Christmas cards. I also made some Halloween garlands for DD who is in her first year at uni to decorate her flat kitchen with. White ghosts, orange pumpkins, black cats, all stapled to a long piece of wool.
I agree that dies are expensive - I dread to think what the total cost of mine was, definitely in the hundreds! But I have no regrets about buying it. It's been occasionally useful over a period of 15 years plus.