Subscribe Today have a "Summer Sale" on at present where you can get 6 issues of monthly magazines for $15.
Lots of titles to choose from.
Be aware that it will put you onto a rolling 6-month subscription after your first 6 months so if you're not wanting to continue the subscription remember to cancel it.
They don't have an end date to the sale listed on their site other than calling it a "summer sale" so it's anyone's guess at to when this sale ends.
Better Homes & Gardens
Also available WHO and New Idea are both 6 issues for $6 however those are weekly publications.