Answering your question whether car bike racks are expensive or not, a car bike rack usually costs around $30-$2,000, which is quite a wide price range. To be more specific:
- Trunk-mount bike racks cost $30-$400 (for the whole rack, which can fit up to 3 bikes),
- Roof bike racks cost $70-$400 per bike place and $200-$2,000 for the whole roof system (highly depends on how many bikes you are planning to transport),
- Hitch bike racks cost $200-$1,000 (for the whole rack, which can fit up to 6 bikes).
Also, you need to keep in mind that some bike rack types also require an installation system (roof bike racks and hitch bike racks do), which is going to add another $200-$800 to the bill.
I get that the above price ranges are very wide and not quite helpful as a result. So let’s narrow it down a bit and go through each bike rack type. Moreover, I will cover the installation costs as well.
How much do trunk-mount bike racks cost?

This is the cheapest option with a big gap. On top of that, trunk-mount racks are getting installed on a car out of the box. You don’t have to buy an installation system, which is going to save you a decent chunk of money.
Mass market segment: $30-$150 for the whole rack.
Premium segment: $150-$400 for the whole rack.
The price depends on how many bikes a bike rack can fit (from 1 up to 3 bikes), where one-bike racks are the cheapest.
The bottom line is that you can buy a trunk bike rack of decent quality for just $100. Don’t get overexcited though since trunk racks pose the highest risks to damage your car. So there are good chances that you won’t save money, pretty much the opposite might happen. As a result, especially cheap bike racks aren’t worth it. Though if you are planning to use a bike rack very occasionally then it probably won’t be a problem.
How much do roof bike racks cost?

Here it gets a bit more tricky. You can’t simply install a roof bike rack on top of your car. You need a roof rack or crossbars as well (don’t confuse them with roof bike racks).
The cheapest rack installation option will be around $150, whereas the premium segment is somewhere around $400-$800 (for the whole system).
Then, you need to buy a roof bike rack itself, obviously. A mass-market roof rake normally costs $70-$100 for each bike place. A premium one will be $150-$300 for each bike place.
Summing up, the cheapest roof rack system that can only fit one bike will cost you within $200. Though don’t expect to get good quality for this price.
A roof bike rack system of good quality will cost you approx $700 ($500 for the installation system + $200 for one bike place). If you need to transport more than one bike, then add $200 for each extra bike place.
How much do hitch bike racks cost?

In order to install a hitch bike rack, your car must be equipped with a towing hitch receiver. Some car models get it installed by the manufacturer. If you are not lucky to have it preinstalled, then be ready to pay $200-$500, plus $100-$250 for the installation. That’s how much it cost to install a hitch for a bike rack.
As a result, a trailer hitch receiver will cost you around $300-$750.
Then, you need to buy a hitch rack itself:
- Platform (tray) hitch racks normally cost $400-$1,000 (for the whole rack which can carry 1-4 bikes),
- Horizontal hanging hitch racks cost around $200-$600 (for the whole rack which can carry 1-5 bikes). And you actually can buy a decent one for $200,
- Vertical hanging hitch racks are designed to carry up to 6 bikes and can cost up to $1,000 for the whole rack.
Summing up, the cheapest platform (tray) hitch rack will cost you $700, the cheapest horizontal hanging hitch rack will be around $500, and the cheapest vertical hanging hitch rack is probably around $900. All prices include a hitch receiver. The good news is that even the cheapest options are produced by premium brands (Thule, Yakima, Hollywood) so the quality will be there.
Are hitch bike racks worth it? Yes, they definitely worth it since a) this rack type poses super-low risks of damaging your car, b) you can easily open the trunk with a loaded rack, c) it is much easier to put a bike on this rack type since you don’t need to perform any lifting.
Why some bike racks are so expensive?
The reason why some hitch bike racks are quite expensive is that it is necessary to basically install a second pair of tail lights on them.
Conclusion
Trunk-mount bike racks are the cheapest ones but can damage your car.
Roof bike racks are quite expensive, and it is not that easy to put a bike on them.
Hitch bike racks are the best option in my opinion. Yes, they are not cheap, but definitely will be worth the money spent.