I have a two fold "problem" with PIL :
My dds are 5 and 4. In previous years Christmas' , PIL have asked me for ideas of what to get the dds for Christmas .
I have given them ideas , they seemed happy and accepted so I've taken the items off my list . Only on Christmas morning , for there to be no sign of said item as it has been replaced by some other random item usually tat
Last year they asked dds what they would like from Father Christmas and naturally the DC mentioned a couple of things - so PIL then decided that they were getting them those items . I got round this by telling them I had already bought the items (I didn't want disappointed children on Christmas morning when the items didn't appear).
PIL have visited today and asked me for ideas of what to get the dds . I don't really want to give them ideas as I spend time thinking , then they don't buy it anyway !
They have also decided to cut back the amount they spend on the DGC (no problem at all) ; their budget is £20. Again no issues .
The problem is , instead of buying one or two good quality items , they spread the budget out on tat to make it look more 
Dd1 present last year fell apart in her hand as she opened it and she was upset .
Dd2 cut her hand on her present as the plastic was so cheap it snapped in half 
I would much rather they spent a few pounds on an orchard toy game or puzzle etc than buy lots of cheap rubbish which goes straight in the bin.
Is there a way to politely say this or do I just grin and suck it up ?
And should I give them some ideas or let them do it themselves ? 