I agree whole-heartedly, you can fix it.
And before this happens on the other side... The rubber grommets where our sidecovers pop in were really tight and hard on my bike. So I applied a light coat of silicone grease. (I used over-priced "Scuba" grease... $8 for a tiny, tiny jar) It won't be slippery enough that the covers will go flying off on the freeway, but it will help preventing breakage.
Repair is definitely worth your time. It's cheaper for one, but it's an opportunity to learn a new thing to do on your bike.
If you fail, you can always shop for a new one later -- used or after-market.
I too successfully fixed a broken sidecover on my K4 where the entire bottom tab was busted off and missing. Oddly enough, I had a second side cover where the top was entirely missing, but the bottom tab was in tact, so... Franken-cover.
I used a white "thermoplastic welding rod" and a soldering iron... there are several ways to deal with this, but whatever way, I think you should go for it.