It is remarkable for lengths transsexuals will go to in order to modify their voice , I was trawling the Internet and I found some fascinating information on the cost of a male to female voice change;

$7,000 (approx £4,600) for the surgery which includes a reduction of the thyroid cartilage (Adam's Apple).

In Amsterdam a consultation with Prof H.F. Mahieu to see if surgery was feasible cost approx 200 Guilders (£180) and surgery about 3,000 guilders (£1,200).

the article is very interesting, if you have a fascination for surgical process, then you should read this : http://www.g7ucl.fsnet.co.uk/voice.htm