Renting a Car: Is It Worth It?

My answer is a bit off-topic:

1. The roads to Tashkent are terrible, and you'll get very tired sitting in traffic jams.
2. A taxi from Samarkand to Tashkent costs about 600,000–800,000 Uzbek soms for the entire car with a driver. Out of that, the driver spends roughly 200,000 soms on fuel, so the savings from driving yourself aren't that significant. Drivers also carry parcels and deliveries, which makes it more worthwhile for them than for you.
3. There are a huge number of speed cameras and populated areas along the route. You could easily end up with a few hundred dollars' worth of fines for driving over 70 km/h.
4. There are air-conditioned buses. Tickets cost around $8, and the journey takes approximately 5 hours and 30 minutes.
5. It's better to have a local person negotiate with taxi drivers on your behalf. Otherwise, they'll probably try to overcharge you.
6. There are traffic jams inside the city all the time. Having a car won't really help. In fact, Yandex Taxi will probably get you around town faster.
7. The security deposit for a rental car is usually not returned immediately because traffic fines cannot be verified in less than 24 hours, as far as I know.
8. Car-sharing services are not designed for intercity travel. If something breaks down, you'll lose at least a full day of your valuable vacation time.
9. If you're leaving Samarkand toward the end of the week, you may be able to find a car for 450,000 soms. We managed to negotiate that ourselves about a month ago.

Of course, the decision is yours.

Good luck!