Co-sleeping with your baby is a great way to enhance bonding and makes it much easier to handle feeding in the middle of the night. However, pediatricians raise very legitimate safety concerns about sleeping in the same bed with your baby.
Our solution is a sidecar cosleeper that sits beside the bed, putting the baby right next to us, but with her own sleeping area so we won't accidentally roll over & squish her. I've made three of these over the years using standard dimensional lumber. You can make your own in a couple of hours.
The materials and dimensions listed in this instructable are for a 38" X 24" mattress that is 2-1/2" thick. (This is the standard "compact crib" size.) You can easily adapt the design for any size mattress.
The lumber is dimensional lumber in US sizes.
When I made this, the lumber cost $30, the screws $7, and the mattress $25.