Ebay is a great place to buy second hand miniatures.
Miniatures by post is a good place to buy new warhammer it has a 20% discount on most games workshop products.
Unit fillers can help to stretch the models you have
further, for example you could have a 40x40 base with a slayer fighting
a troll in a unit of slayers.
Battle for skull pass is good for starting out but also for expanding an existing army, it has 616 points not including
magic items and it has loads of goblins witch you can sell.
