Well, if you’re definitely only interested in top-of-the-line choices, so a 4090 for GPU and either a top-end Intel 13th gen or an AMD 7000 series + X3D as the CPU, then yeah, you’re going to have to hold your nose and spend the money.
GPU prices are unlikely to drop much for current-gen cards. Poor availability is still a thing, but not so much of a thing as it was in 2020-2022. The Nvidia MSRP for the 4090 is (in GBP) £1600, and while equivalent pricing in other countries is not a simple matter of exchange rates, it’s not going to be substantially cheaper anywhere else. Scan, as mentioned above, has plenty of 4090s in stock for prices between £1650 and £2200. Prices are not artificially inflated because of scarcity, the way they were not so long ago.
CPU pricing is what it is. Intel and AMD will always charge top dollar for their highest-end CPUs. I tend to be more willing to compromise a little on the CPU than the GPU, because if you go for the right chip and are able to overclock it well, you can get very close to the top-end performance with a substantially cheaper chip. But then this is the guy who swapped out a 12900K he had only bought six months before for a 13900K to get a very modest performance improvement, so I’m maybe not the best person to ask about budgeting.
Assuming you’re in the EU (since you’re quoting prices in Euros), is it even a thing to maybe get someone to buy components for you in another EU state where there is availability and ship them to you privately? Cutting out the middle-man can save a lot of money, and system builders have to make their money somewhere. This is why I always build myself.