Wow, that's a big budget.  You can almost get any type of case, except the gold plated, diamond studded customized cases

There are quite a lot of cases out there in the market.  Its hard to recommend to you if you simply give us a budget.  You have to first decide on the following:

1. There is the Apple's design Smart Cover, but need to be coupled with a good back casing (to protect the back) - back casing includes those made by SwitchEasy, Ozaki, Speck, GGMM, Incipio, iLuv etc

If you don't like (1.), then proceed to (2 & 3)

2. Choose between Back Casing Only / Slip case / Folio Type / Rugged
3. Do you want light weight / slim or do you prefer better protection over weight/slimness
4. Do you type often and need a keyboard? because some cases comes with Bluetooth keyboard.

Once you narrow down to the descriptions above, come back here and ask again.  Then we have a better idea of what to recommend.