Clearly, hiring a lawyer will cost you legal fees, and not hiring a lawyer will not.

If you're asked about marriage and deliberately lie, on the basis that you think the lie is "irrelevant" to the instant visa application, even if your assumption is correct it can turn around and bite you in the posterior when you later try to use your marriage as a basis for immigration. "You say you were marred in 2007, but on your visa application from 2009 you claimed to be single." At a bare minimum you raise questions as to whether you have a bona fide marriage.