These pencils are very highly regarded among professional artists. This set is RRP$144.95 at Eckersleys.
AUD$10 cheaper than last time I posted them.
I have this set and there aren't any gaps in it for me. You can buy single pencils at Eckersley's for $2.95 if you find the 72 set doesn't cover all of your needs (very unlikely).
Google Images link to show what these pencils (in the hands of a good artist) are capable of.
It shows $21.77 for me?!