I offer remote trombone sessions, and sundry transcription/arranging/part preparation services at competitive prices based on MU guidelines. Email for a quote, or here are some off-the-peg options:
Trombone track for one song
Recorded according to your instructions (sheet music, guide audio, vague adjectives...)
Rath trombone -> EV RE20 -> Apogee Duet -> WAV (up to 96kHz/24 bit). £30 / £40