The lawyer gave you completely wrong information. There is no minimum-income requirement for sponsoring a spouse, unless that spouse has a dependent child who has a dependent child of their own (i.e. a grandchild).
Just occasionally, an issue comes up where an IO invokes
A39. This is a second financial requirement that doesn't come up often. It is not based on the sponsor's income directly, but rather a requirement that either the PR is able and willing to work, or there be sufficient adequate arrangements for their support.
"Financial reasons
39. A foreign national is inadmissible for financial reasons if they are or will be unable or unwilling to support themself or any other person who is dependent on them, and have not satisfied an officer that adequate arrangements for care and support, other than those that involve social assistance, have been made."
See also
OP2 section 10.3:
"Sponsors of dependent children and of spouses, common-law partners or conjugal partners
(unless they have dependent children who have dependent children of their own) do not have to
meet financial requirements, but they do undertake to provide for the basic necessities of the
sponsored applicants so that the applicants do not need social assistance.
Applicants may be
refused for financial reasons under A39 if they are unable or unwilling to support themselves and
their dependent children and there are not adequate arrangements for their care and support.Officers should take into consideration the sponsor's financial situation and willingness to assist,
as well as the financial situation or employment prospects of the applicant, if applicable."
So, in theory, if the sponsor was on a very low income, and the applicant was unable to work, you could be refused. However, as long as you are able and willing to work (at all, in any job), that would not apply, so there is really nothing to worry about.
Matthew