MYSQL DECIMAL(5,2) returns 999.99 instead of the input value (82.50)

MYSQL 5.5 / PHP plugin to WordPress, using HTML forms for input

This is similar to the problem mentioned in 999.99 Value for 1138 In Mysql/PhP My Admin but NOT THE SAME!

The values my users need to enter in my online form will never be larger than 999.99 for this one field (column), so why is MYSQL giving me 999.99 when I enter 82.50 ? The error is not just in the frontend, on viewing the form - the form allows me to enter 82.50, but then displays 999.99, and this is the value in the DB column too.

Any ideas, please?

via Chebli Mohamed