I also just decided to start out with a field grade Beretta semi-auto, though I'm picking up a sporting O/U pretty soon.
There's actually something nice about using a lower-end, no-frills gun when you first start out because for one thing, you don't exactly know what bells and whistles you want yet. Secondly, when a person shows up to the range with a $5000 custom made shotgun, you expect
them to shoot at a $5000 level. It's like when you see a guy in a Ferrari take a hairpin turn, you really expect him to do it with some skill. There's nothing sadder than a guy driving a $150k car who doesn't know throttle oversteer from a hole in the ground. :wink:
I witnessed it just yesterday... One of the regular members shot a perfect round with his old and very beat up Remington pump, while the guy with the custom shotgun missed as many as he broke.
Of course, there's also something nice about having a gun you can grow into. But in the end, I'd just focus on fit and comfort and let that be your one and only priority