I would second the suggestion that you investigate rates booking thru a SA agent. I booked in the US and based on what I heard from SA visitors, I overpaid. There are packages available thru SA agents that include local airfares and hotel.
Remember, Vic Falls is a very small town. I don't know what the population is, but I grew up in a town of 6,000 that seems incredibly large in comparison. The core of the town is only a couple of blocks and almost everything closes by dark. Therefore, you will be in your hotel from sundown until morning. Pick a hotel that you can hang out in.
I would not recommend walking or venturing out after dark except where there is security. I walked from the Victoria Falls Hotel to the Kingdom (which is literally next door) after dark for dinner, but that was on a semi-private road with plenty of security. I would not consider walking around the town after dark and I would be be careful getting out even by taxi at night.
Don't discount the Kingdom based on my "Disneyesque" discription. I meant that in the way that it is clean and sanitary and predictable. It is a western hotel with airconditioning everywhere and well-maintained. I would probably choose the Kingdom for my next visit. The proximity to the falls of the Kingdom and the Victoria Falls Hotel put them at the top of the list.
The Victoria Falls Hotel is air conditioned only in the private rooms, not the public spaces. The Mercure has exterior walkways similar to a motel. As the Mercure is really at the heart of the town, you def won't want to venture off of the property at night, but it would probably be my budget option.