I don't think it's an issue at all if you pay it off. You're not an indentured servant, the training contract is just a financial contract (which you intend to honor).

You would not want a reference call to uncover the fact that you had skipped out on a contract without paying, and you would not want a lawsuit against by a past employer for that reason.

Don't sign a training contract if you can't honor the terms (time served or reimbursement). Never ever sign a training contract which requires time served but has no buyout option... then you are stuck, and can (and likely will) be abused horribly.