To clarify, the BOI is the Board of Inquiry on Faunaclassifieds.com. It's a good idea to check there, but it might be easier, since you are looking for some specific snakes, to find them for sale and look for the particular seller in the BOI.
You can probably find a female pastel in the 800+ gram, breeding size morphs are hard to find. Expect to spend up to $800-$1000. A breeding size male spider or pastel should be fairly easy to find and in the ~$400 range. I haven't seen many, if any, 2007 or older spider females.