Replying to S*** fitting boots, Any help?

I have been skiing on these pair of 3-4 year old nordicas i picked up at a garage sale for 40 bucks. There not bad boots (nothing compared to full tilts). They are fine fitting around my shin but down to my ankle and foot but there is a shit load of room ( i can lift the ball of my foot up and down in them). I have been wearing two pairs of socks which fixes this problem, but my feet get all sweaty and hot and it sucks. Is it possible to buy some sort of liner that could make my boots fit better? I need help. anything will be appreciated.