Very much agree with the two posts above.
If I had the time, I could type for hours about why flying is cheaper in the USA, but a few little examples will do.
USA: Installing an EHSI (N-reg plane) is a minor mod.
UK: As above (N-reg plane too) "needs" a DER, 337, this and that, £1000 in paperwork.
USA: Installing 2xGNS530W (N-reg plane) is a minor mod.
Europe: As above (Euro-reg plane) is a Major Mod, paperwork fees into 4 digits.
USA: FAA DAR charges $300 (N-reg)
Europe: FAA DAR charges £1300 (N-reg)
USA: landing fee at a major airport = 0
Europe: landing/handling fee = £150
One thing a sharp reader may notice is that none of the above are really connected with trading volume. They are purely "attitude" issues, with no logic involved.
There are many "trading volume" savings of course. Interestingly, a lot of these can be "imported" over here... e.g. you operate a fleet of 10 C172s; you can buy all the parts for them mail order from the USA (an FAA 8130-3 form is fine for a non-AOC G-reg) in bulk.