M.L.
We have the Sony monitor and it works great. It runs around $50. We live in a 3-story home. My son's room is on the 2nd floor and we are on the 3rd floor and have not had any issues at all. We got it before he was born and he is now 18 months old and we still use the same one. We can hear him really well if he cries or even makes any noise. I love our monitor and would definitely recommend it.
-M.