it varies quite a bit from season-to-season and world-to-world.
One season you may be able to recruit a #150 SF, the next season you may not be able to get the #200 SF.
You could do a search at the beginning of recruiting of D1 recruits by position.
This certainly is a rough estimate, but you may see about 60 of those guys drop, or open to recruiting by a D2 team at your level. That 60 is probably on the low end. You may find 80-100 that are available some seasons.
So if you see 250 PGs listed on your D1 search, your top end may be in the #190 range. that's the 250 total minus the 60 that may drop. If it's 80-100 that will drop, your cap is closer to the #150-#170 PG.
But you really may want to contact several guys initially to find your cap. Call the #200, #190, #180 guys and see if all or any of them are giving you the backup message.