[SKI]

There is absolutely no reason to buy any Avid interface from the range formerly known as LE.

Just purchase a crossgrade from your LE to PT10 then buy a quality interface.
You can continue to use your mBox 2 while you decide on an better interface or raise additional funds.

The feature set of 10 is well worth it if you plan to continue to use PT the hardware not so much.

While the mBox 3 sounds way better than the mBox 2 and allows for better features it also has some issues that Avid seems to not care about resolving.
Since you are no longer tied to the Avid hardware with 10 why add the additional headache?