Supply and demand.

As of this post, 19 teams have all 5 BRBs for this season already on the roster.  5 more teams have 4.  That accounts of 24 of the 30 teams, or 80% of the league.

Further, if you look around on rosters, there are at least another 15 age V players who could still be BRB material this off-season.  That's would leave just 3 or so teams not fully stocked.  With so little need, it is entirely a buyer's market for BRBs right now.  I've found myself with extra age V guys and in order to sell them I have to 'underbid' them to other managers who are getting similar offers from other teams with a glut of old guys on the bench.

So because of the high supply available, I think that leaves us with needing to either fight the price drop by limiting supply, or meet the demand where it's at and drop the price.

Dropping the price at auctions to 100 for an age II and 150 for age I, or 125/175, would probably bring about a lot more bidding on BRBs instead of buying them at that price from other teams.  Better to give the money to Olmec than another manager who will use it against me in the future!

In order to limit supply and force the demand and prices back up to the 250-300 range, we'd have to make it harder to make a BRB.  Options are increasing the SL needed to make one (age V, SL V minimum for example, which would cut the pool of available guys in half this preseason) or push the age back to age VI, which is truly a rare beast in this league as in order to get there you'd have to get a player to age V, SL 8, which means they were age VI, SL 13 (getting one SL while age IV if they were an age III, SL 16 max player).  Planning for and creating BRBs internally would get a lot harder, so the price to buy them would go back up in a hurry.