Think of the consequences, imagine a life where you see people having sex, gfs, and you wanting those things but decide only to fap, what will happen is that you will get depressed or frustrated with time. Now imagine you're an incel with a small social circle, and hearing your friends discuss about sex and girls and you can only talk about fapping like some 8th grader, same, you will get depressed and angry because you will feel left out.
Now imagine being an incel with no friends and social life, and just fapping for the rest of your life, does that sound good to you? I know a life like that will end up with me having soul crushing depression. Life's already hard for people who fuck and are in relationships, now imagine life for those who don't get any.
If paying for a whore can lessen your pain and make life more bearable or enjoyable, I say go for it.