Just some stuff about export/import :
For a 1500 CHF new laptop, you will be legaly obliged to declare it at customs, even if you will bring it yourself. You will be able to get the 7.7% Swiss VAT refunded and on the other hand you will have to pay the 23% VAT of Poland. Some duties might apply. you can check it on the tariq website of the EU
At an airport, they will look for new packages specifically.
You can check the applicable code on this website. you will also need the origin of goods :
TARIC Consultation (europa.eu)
It seems that the tarriff code for Laptops is 8471300000, therefore the duty according to the website is 0% (I assumed origin China).
That would be for the legal side. So in this case, even if you bring it yourself, you will declare export here, get 7.7% back and declare import in Poland, you will have to pay 23%. BTW, the VAT of the receiver is mostly paid by the receiver if you use a forwarder, + a fee for the customs paperwork.
As a general advice, I would like to point out that people often forget that Switzerland is not in the EU, and that in this case customs and tax regulations also apply to private citizens. Especially for valuable items like in this case. In this case, buy the product from a merchant in the EU, even if it seems less expensive. The hassle will be different as you can experience now. (Can you still send it back and buy it from a local merchant in poland ?)
EDIT : BTW, the offers you got until now do not include VAT and Customs, as well as Custom declaration fee levied by the custom agent. Except if they say it is DDP (Incoterms 2020).
EDIT 2 : if you go yourself by car, you might have to declare only at the country of entry. In this case it would be Germany or Austria (most probably). Not sure about that though, could be you have to declare Transit at each different country.