The AIU books are way low on my list of pre-code horror in terms of desirability, art, etc.
I used to go out of my way to avoid this "lame" publisher myself, but as I began to try to put a complete AIU pch run together over a year ago, my appreciation for them has grown. Despite an array of bland covers, there are many gems scatterred through the series.
If you find time, check back at my posts in this thread over the last few months, the ones with scans are mostly AIU. You might find a few to be pleasantly surprising.