If the tax is high for you, then it means you shouldn't import it. Declaring fake amounts will only give you trouble. You'll lose more than the tax money and risk yourself for a jail sentence.
Risk jail sentence? For under-declaring imported goods? In what country?

But still, I understand trouble for refusing to pay fine once caught, blah blah. But not just for under-declaring goods value! Imagine making typo in customs declaration and insta prison lol. This does not happen.
we'd better follow the local rule to avoid more troubles.