Anything free is in our budget range
so we like:
old socks with an old washcloth stuffed in them, then knotted
heavy plastic tubs or bottles (like the Costco peanut butter jugs, you can stuff another toy in it and she'll go nutty trying to pull it out)
bubble wrap (only lasts a few minutes but it's fun)
plastic tubes (like water hose or vacuum cleaner-type hose) (all clean of course)... if you blow through one end or make noises through it, Mango will really get excited about it.
We quit using the colorful store-type rope toys after I had to help pull long threads out of "her other end"
one day.