I feel the same way sometimes, but rest assured.
Even when we were married, STBX had to buy them EVERY Thomas Train, ALL the tracks and buildings, EVERY superhero, EVERY car.
And did he ever sit and play with them?? NO!!
Who built all the tracks and set up the buildings? ME!!
I even bought them a boy's like dollhouse, one just made of wood with ladders and different rooms, and our superheroes had a "fort" to play in, plan their missions, save each other, etc..
It's all about spending the time with them! Buying them stuff doesn't mean crap if you just give it to them and tell them to go away, which is exactly what he does..
DS9's favorite thing to play with right now is Total Drama characters, that I printed off Google images in black and white, and he makes teams and "eliminates" people, and he has a ball. And if he loses one, I just print off another one. It has cost me PENNIES to have the best time playing with the kids..
You really can find very cheap ways to do fun things with the kids. It's like when you buy them a $100 gift and they play with the box.. It's all about the time you spend with them, getting to know them, finding out what they like and don't like, and I find it to be a fabulous time to throw in a few moral and life lessons and to teach them about appropriate behaviors (one of those Total Drama characters is a real asshole, lol).
Do you have a computer and printer? I would try printing off the characters from their favorite show and having some adventures. There's no reason to spend hundreds of dollars on real figures..
Good luck!! Hugs!!