Shoes

I am a little annoyed that my recently purchased new Asics (verdict on last pair: awesome) give me massive blisters even after 40 minute runs. I am now in a bit of a dilemma. I am doing an Alpine half marathon in the summer, for which I will most certainly need trail trainers for (I've got my eye on a pair of Salamon ladies). But I also think I ought to replace my normal running shoes before they destroy my feet and my will to live.  Which should I prioritise? The Alpine half is my big ambition of the year, but it is in July and I'll probably be able to get some before then. My running shoes hurt me.
I think the replacement pair must take priority, but I am impatient to get the trail shoes. They will help my mind power for the Alpine training...