Wedding ceremonies are great experience. Check out the facility, be sure there is a coordinator, if it is a Mass, confirm if they want the mass parts played etc etc. Always attend the rehearsal. Even with prep, you may be fighting for space with the photographers or other soloists. The experience i referred to was experience in being flexible and capable of working around the unexpected.
Years ago i did it for $75 to $100. Now base fee is $150-$175. I may bump it again -- My daughter is getting married next June and as i review the costs i have concluded the industry (wedding services) is is pretty impressed with itself.