Foot and Mouth disease is a little more severe than that, Ryan. You don't just get a fever, some blisters in uncomfortable places and then in a few weeks everything is magically fine. FMD can be fatal to young/weak animals, and those that survive are often debilitated. The animals lose considerable weight, produce less milk and abortions do occur. If the problem isn't dealt with, secondary infections are frequent.
The virus can survive for relatively long periods of time in the air, in food and garbage, and even in hides, hair, and wool, so measures for controlling the disease are necessarily rigorous. The only real way to control the disease is by killing the infected animals, burning their carcasses and then cleaning the affected areas.
I'm not sure if the latest moves by the UK are overkill or not, mainly because I don't know what they are (bloody bbc website down as usual). Anyway, I don't think it's unusual for a government to under-react and then move to a plan that might be considered "overkill." Exaggerated moves are just a poltical tactic.
And yes, it does all come down to money, not the animals. We aren't that far away from a vaccine, but of course, the cost to immunize would be far too high.