as far as toys go you can make lots of them yourself, & you can use lots of other cheap alternatives. Just be careful you dont get any rubber toys (kongs may be ok or other really hard rubber but supervise to make sure they dont eat it) here are some examples of what i use

empy boxes (most ferrets like these better than the toy that came in the box)

rice box (fill a rubbermaid type container w/ LONG GRAIN UNCOOKED REGULAR RICE ONLY) they love it

fill a box w/ shredded paper, toilet paper (no rolls though they can become lodged into the tube), old clothes

blankets (they love blanket piles)

dryer hose (the plastic type that stretches)

baby toys (great & cheap at garage sales, thrift stores etc)

most cat toys

plastic easter eggs (can fill w/ pieces of kibble so it jingles & they get a treat if they open it)

plastic grocery store bags (under supervision)

let your imagination run wild, they love just about anything. They do get bored of the same toys so I divide my toys in different groups & alternante what batch they get. I do this every 2-3 days, you can also place them outside so they get different smells on them, its like new toys all over again to them.