Here are a couple ideas that you can use to make some of your own toys and it wont cost you much or anything for that matter if you have the supplies lying around.

Mobiles
Use two coat hangers and cross them over each other like a cross and secure with some tape like masking or insulation tape. Hang some items such as toys or milk cartons covered in gift wrap or contact that is bright and colourful. You can also apply stickers if you like. You hang these items with string or fishing line that is short in lenth. Make sure it is secure.

Bath Time
Cut a 2 litre milk bottle a quarter way down just straight across and take the lid of and keep it. This can be used as a funnel. You can also put the lid back on and fill it with water and then take it off to let the water out. Another idea is get a drink bottle like a empty Mount Franklin bottle fill it half full or just over, put some food colouring like blue or green and cut up some sponge peices into say fish and put in the bottle. Seel with the lid and you have a little aquarium the kids can play with in the bath.

Pram or in Car Mobiles
You can use plastic rings or even tie a couple of soft toys and plastic lids from milk bottles or jars and make a fairly big hole in it and attach these to plastic string or some elastic. Make sure its firm and pulled tight. Attach this to the pram or a car capsual and you have yourself a mobile.

I hope these ideas help. They are easily affordable and quite easy and fun to make.