Resuggestion, thanks to Cashew for the info!

Sale 1:

https://backpack.tf/profiles/76561198177719569#!/compare/1581120000/1581206400

https://backpack.tf/profiles/76561198886850124#!/compare/1581033600/1581206400

https://backpack.tf/profiles/76561198804445167#!/compare/1581120000/1581206400

https://backpack.tf/profiles/76561198255568360#!/compare/1581292800/1581379200

untrace

Sale 2:

https://backpack.tf/profiles/76561198255568360#!/compare/1581379200/1581465600

https://backpack.tf/profiles/76561198852524025#!/compare/1581379200/1581465600

https://backpack.tf/profiles/76561198852524025#!/compare/1581465600/1581552000

https://backpack.tf/profiles/76561198281630040#!/compare/1581552000/1581638400

https://backpack.tf/profiles/76561198177719569#!/compare/1581465600/1581638400

https://backpack.tf/profiles/76561198087494715#!/compare/1581638400/1581724800

Untrace / bulk / gambling

Sale 3:

https://backpack.tf/profiles/76561198066813088#!/compare/1583452800/1583539200

https://backpack.tf/profiles/76561198957518408#!/compare/1583452800/1583539200

https://backpack.tf/profiles/76561198257264924#!/compare/1583366400/1583539200

https://backpack.tf/profiles/76561197994697258#!/compare/1583452800/1583539200

Untrace / bulk

sale 4:

https://backpack.tf/profiles/76561198117834497#!/compare/1584662400/1585180800

https://backpack.tf/profiles/76561198085685517#!/compare/1585008000/1585094400

Bulky

sale 5:

https://backpack.tf/profiles/76561198085685517#!/compare/1585180800/1585267200

https://backpack.tf/profiles/76561198156407608#!/compare/1585180800/1585267200

Sold with ~0.51 keys in sweets for Bubbling France(16)

total is ~15 keys

https://bot.tf/stats/listings/4KVVVOJE

B/O of 18 keys

sale 6:

https://backpack.tf/profiles/76561198156407608#!/compare/1585353600/1585440000

https://backpack.tf/profiles/76561198088551406#!/compare/1585353600/1585440000

sold with ~1.5 keys in sweets for C9 Ninja Hood

Hood Mini:

https://backpack.tf/suggestion/5ea64a3594076127487e5240

Suggestion for 18 keys

Total is ~17 keys

https://bot.tf/stats/listings/MGLL85XQ

B/O of 18 keys

Sale 7:

https://backpack.tf/profiles/76561198088551406#!/compare/1585440000/1585526400

https://backpack.tf/profiles/76561198066714060#!/compare/1585440000/1585526400

Sold for keys

sale 8:

https://backpack.tf/profiles/76561198066714060#!/compare/1586217600/1586476800

https://backpack.tf/profiles/76561198964551276#!/compare/1586304000/1586390400

Sold for 15 keys

sale 9:

https://backpack.tf/profiles/76561198076413900#!/compare/1580169600/1580256000

https://backpack.tf/profiles/76561198821294885#!/compare/1580169600/1580256000

Bulk

sale 10:

https://backpack.tf/profiles/76561198821294885#!/compare/1580169600/1580256000

https://backpack.tf/profiles/76561198080425549#!/compare/1580169600/1580256000

Sold for 11 keys

sale 11:

https://backpack.tf/profiles/76561198080425549#!/compare/1580256000/1580342400

https://backpack.tf/profiles/76561198159795444#!/compare/1580169600/1580342400

Sold for 14 keys

sale 12:

https://backpack.tf/profiles/76561198056804742#!/compare/1581206400/1581292800

https://backpack.tf/profiles/76561198158685215#!/compare/1559001600/1581552000

Sold for 14 keys

Sale 13:

https://marketplace.tf/items/tf2/106;5;u61

$30.99 / $1.77 = 17.51 keys <--- https://backpack.tf/item/1789303578

$19.3 / $1.69 = 11.42 keys

$30.05 / $1.77 = 16.98 keys <--- https://backpack.tf/item/7956659982

Total sales @:

11, 11, 14, 14, 15, 15, 17, 17, 18 keys

buyers up to ~14.5 keys,

sellers at 16, 18 keys

one 18 key unsold for a month:

https://bot.tf/stats/listings/4R0DJ08D

calling 14 low,

18 high,

taking 15 - 17 keys, conserves around 16 key unsold.