limited register has NOTHING with determining price...it basically means they are not up to breed standard and are NOT to be bred from.
there usually is a price difference BUT not because they are on limited register it is because that particular dog is not up to standard.
for example....
my boxers...if i have a flashy show quality pup it will automatically be placed on the main register(if i soo choose to put it on the main register, i can place a dog that does meet standard on the limited register if i so wish) (so it can be shown/bred from) and i have a white boxer he will be placed on the limited register as his colour is considered a fault (can't be shown/bred from and does not meet standard)

It is the breeder choice as to wether the dog is placed on main/limited register and they will more than likely charge differently. They also have to provide all papers for dogs!!! they can't say 'oh for an extra $100 you can get his pedigree papers'