For anyone interested, Spotrac has the Bills with $2.564M in cap space under the Top 51 rule and $1.06M with all the contracts.
https://www.spotrac.com/nfl/buffalo-bills/cap/
OTC has an extra $3M or so, but they don't show their work the way Spotrac does, so it's hard to know where they get that from.
Beane stays under the Top 51 until September 10th, so he has leeway in doing some cap "gymnastics".
Signing back Ferguson and Ifedi should add a little over $2M in contract money. PS should add around another $3.7M.
Having the guys go to IR/PUP opens up spots on the 53 rosters but they have to be replaced with other player salaries.
"Stashing" costs money, LOL.
FWIW.