I commuted on an electric bicycle (and didn't own a car) in 2010-2012 on a eZee Torq http://ezeebike.com/bikes-and-options/torq/ it cost less than 2k.

I'm a bit out of touch of the latest developments in the market (I walk to work these days) but I'm sure you can find plenty of good options under 3k.

Bafang BBS is a nice alternative. Goes on the crank shaft and converts most bikes to electric. More powerful than Stromer for fraction of the cost...

Try craigslist. There are often cheaper ones available used. Keep in mind that 30 mi is on the high end of what most ebike battery packs can do.

Stromer ST1 is about that much. ST2 doesn't buy you much more tbh, it has a GPS and theft protection, little bigger battery. $3k actually seems to be the magic number where ebikes are good. Also, as others have said, building your own is a cheaper option. At 30mi you would likely want to charge at work (I do anyway, it's easier on the battery).

Also, FWIW, I was debating a second car (married w/kids) or the bike, and am 100% satisfied with my bike and the price I paid for it