First of all, there's a wide variety of both high-end and economy rental vehicles on offer in Ethiopia. What you end up opting for is largely dependent on your budget and what you plan to do. Prestige vehicles offer unparalleled mod cons and comfort. If you want to treat yourself, why not book a high-end SUV, or perhaps an upmarket medium-sized vehicle? Otherwise, if you're just after a car to get from A to B as cheaply as possible, maybe go for a budget compact vehicle (or something else that's unlikely to break the bank).