I completely okay with porn. Nothing like 2 girls, one cup or 1 guy 1 jar, but BDSM, threesomes, gay, straight, etc. is completely within my realm of acceptability.
Usually I charge 25c a word, so you would be looking at $5,000 for 20,000 words (2,000 descriptions).
I have a history writing creatively and academically. Let me know if you have any questions!
Thanks!