How much can your landlord raise the rent all at once to a new tenant?
It depends on your lease. If you don't have a lease, the rent
can be raised at any time by any amount. If you do have a lease,
check the lease. If their are limits raising the rent in the lease,
then you can bring that to your landlord's attention. If they raise
your rate more than what's in the lease, then you can sue them in
order to get them to comply with the lease. If there are no limits
identified in the lease, then the rent can be raised at any time by
any amount.