I've already given my opinion on the piece, but a few thoughts.
Having the score in front of me is useful:
It's a little curious how much is written in 5s in the rh, but I don't see that it should cause an especial problem. The chromatic 5 in thirds against 3 looks manageable on page 6, but (unless I'm reflecting my own weaknesses unduly) the chromatic 5 in fourths against 3 on the next page looks nasty. Personally I'd consider simplifying it so that only the first dyad of each group is a fourth.
The end of page 12/start page 13 is notationally peculiar. When the falling orchestral motif coincides with the piano entrance, the bottom note falls on the beat; beforehand the accents fall differently. I'm not a mindreader but I suspect you intend that the final note of the previous motifs also fall on the accent. There is also inconsistency regarding accentuation with respect to and in comparison with the occurrences of the motif on page 17.
I have a feeling Liszt would have re-expressed your ascending chordal passage on page 24 in alternate chords (compare the opening of the Totentanz), achieving much the same effect with marginally different notes but making it much more pianistic. I think there are other places where he would have achieved your effects with greater economy (is it really necessary to have so many 5 against 3s - is that cross rhythm there for an actual musical purpose or is it just a historical accident of how the music has emerged?).
In general I don't think it's ridiculously inaccessible and I think any decent pianist (e.g. college graduate) should be able to play this competently given enough time, so tbh, I don't think you need to engage a "virtuoso" - whatever that means nowadays.
As for the cost, I think you're going to pay more than you would to engage a pianist for a random famous concerto, simply because that concerto's probably already in their repertoire and they'll have to do a lot more work with this one.
Thanks so much for your invaluable feedback, ronde.
You must have read my mind in regards to the chromatic fourths. Yes, I did consider that, while the thirds are manageable, the fourths might be seriously problematic given the tempo and I would have to give the pianist that option to use four 16's instead of five unless I instruct the conductor to ritard that measure since fortunately it's at the end of a phrase. I'd leave it up to the pianist since I don't think overall it would hurt the music.
How the 5's came about was that 4's were too few and 6's were too many (unplayable) a problem I had with my 2nd concerto opening interlocking octaves. And I like the sound of an off-number rather than the usual 4 q's = a whole.
Much of that notation with measures in 6/4 and then 4/4 has nothing to do with something I had in mind. Unfortunately, in order to achieve ritardandos the Noteflight notation only allows it by adding extra beats. So if I wanted the solo clarinet to ritard his last phrase I had to add two beats, making it 6/4. That's the only thing that cockamamie odd beat measurements had to do with.
You're probably right about the ascending chords at the end. I just conceived it as chords against octaves to lead into the cadenza burst right before the brass fanfare closes the piece. There could always be an ossia if I can think of one.
So far as cost goes for a name (and that gets back to that 1st, 2nd, 3rd tier business, since Yuja wang would obviously charge way more if she even agreed, than someone like Georgii Cherkin) do you think 5K, 10K, 15K? Can you hint at some possibilities? I have no idea what the business is these days. Used to be you could get someone to learn the Rach 3 for $100 but those days are long gone in this economy.