My two coppers: First, I wouldn't get too hung up on the word "pro." There are many "pro" writers right here on this board who freely offer critiques and/or beta reads. There are many writers with less experience and skill who hang out a shingle and charge for their "pro" services. Sometimes people have an untrue idea that if they pay someone who has put out a shingle, they're getting something better. Unlike many careers, there is no one writing credential that differentiates the pros from the amateurs.
Also, if this manuscript has had no eyes on it other than the writer's, I'd just about guarantee that it needs work. There's no need to pay anyone to say that because any of us who have read lots of unpublished work will say it for free. I have read hundreds of unpublished works whose only eyes on them have been the writer's and I do not recall many, if any, that did not need work.
Finally, the greatest value of doing those critiques and beta reads in exchange is not getting the same back. Imo, it is the very best way to increase your own writing skills quickly. We soon notice the same common few dozen problems in other manuscripts - and then we notice the same ones in
our own writing, when we didn't notice them before. For anyone who wants to write more than one book, that is extremely valuable and you don't get it when you just pay someone to go over your work instead.
Finally, for those who hope to avoid public exposure by paying for a private assessment etc., that is not such a great idea if you hope to have your work published. Getting used to critiques behind a password and by other writers is a far kinder introduction to reviews.
I'd urge you to re-consider the question. Either way, good luck.