Hopefully a New Umpire here.

[Delaware Blue]

As others have said, plate shoes are a must. Even if you wear catcher's shin guards, your toes will be exposed. One shot there will make you regret the decision of not buying plate shoes. If you’re going to work the lower levels, you may get away with a pair of black steel-toed athletic work shoes. But if you’re going to spend the dollars for those, spend a few more for real plate shoes. Also, don’t by cheap shoes. If your feet hurt, it’s hard to concentrate on your job. A good light weight mask is also a plus.

You can also find good used equipment. Many umpires upgrade during the off-season or try a piece of equipment and find they don't like it (or find something else they like more). I have a West Vest Gold chest protector that is a few years old. I'm going to sell it along with a pair of Douglas shin guards. They're in good shape and the only reason I'm selling them is that I bought a Wilson Platinum and Gerry Davis shin guards. I'll probably sell both for less than the cost of the chest protector alone. So it's worth looking for used stuff.

Remember, it doesn't pay to buy cheap equipment. Eventually, you'll regret it. Not only will you buy it twice, but you may have a doctor's bill in between.