I wonder why your electric seat is not charged extra. However if yours is a 320d executive than partial electric seat is now standard (according to the Mar07 pricelist). Note that full electric seat costs you $2750 (non-exec) and $1750 (executive).
Also according to the same pricelist, Comfort Access is now standard for all 3 sedan, while PDC-rear and Anti-dazzle interior mirror are now standard for all 320i/d sedan (323i/325i/335i has this option as standard in Jan07 pricelist). Total of these 3 standard options is around $2500