wanting my rainbow!😭

Ch
so i've had two miscarriages, one in 2013 (April) and one in 2014 (August). i've wanted a baby ever since my first pregnancy, and i even felt ready to have a baby from then, despite the fact i was only 18 at the time.
last year my boyfriend and i decided to ttc... then he changed his mind, after there being a high chance i was already pregnant. he kept saying he wanted a baby and to start a family with me.
now, fast forward three months... we're now engaged and im moving in with him, and now he doesnt say anything like that and when talking about it, he now says 'IF' we have kids... he seems to have changed his mind about wanting a family with me, but all i really want right now is my rainbow baby! he says a baby is too expensive, and yet he's fine with spending $1000 on a graphics card and $500 on a new gun and i've lost track of how much he's spent and is intending to spend on video games! he is so selfish, HOW can he think that something so materialistic is worth more than our children!! im so angry about it, to the point where i've even thought about leaving him.
am i being unreasonable? or am i right for feeling like this? im so sick of him saying something and then going back on his word!!😔😡