In the UK you can have to pay extra taxes first import duty, which i've had to pay before at 45% of the value of the goods
That depends on the goods and the country of origin. For example, a lot of measurement equipment from most countries is taxed with 0%, i.e. nothing. You can look that up in a database called TARIC. If customs gets it wrong, and they sometimes do, you can formally contest the customs duty, and then it really helps if you point them to the correct TARIC number.
There are of course special circumstances, e.g. if customs has reason to belief something is wrong and suspects some cheating, smuggling, etc. E.g. the stupid idea to declare something as "gift" and thinking customs is so stupid to believe it. Then customs might ask for some punitive duty.
plus value added tax at 17.5%,
You would have to pay that also if you would have bought it in some shop in the country.
then on top of that there is handling charges
That is typically charged by the carrier / courier service for dealing with customs. Some carriers are exceptionally bad. E.g. I avoid UPS because of their fees.
Some distributors covers these costs, because they have special deals with some carriers. But that sometimes doesn't stop the carrier to charge you again. Then it helps to complain to the distributor, as they typically care. Complaining to the carrier is usually pointless.
The classic postal service, or what remains of it, often have the lowest handling fees. Sometimes even none at all. The disadvantage is that the classic postal service is usually the slowest and most unreliable carrier.
I have experienced this importing some equipment from USA.
You should really have checked the paperwork to figure out why. I have imported measurement equipment from the US, and the customs duty was 0%, not 45%.