we paid something like £5 per minute of cine film to have them transferred to dvd last christmas. we had ours done by a local camera/tv/photograhy shop as i was very uneasy about posting them off to a random company, they're far too precious to have them get lost in the post. my sister died 3 years ago and that was the reason we finally got round to doing it, with copies for her three girls.
whatever it costs, kate, it will be well worth it. just be prepared to have a box of tissues at the ready when you view them.