Anything over 18 keys is gonna look high given the sellers at 18 keys on both Specialized Killstreak and Basic Killstreak, can include 18 though with a sale at that value. All sales above 18 were on a Killstreak version anyway
Buyers are only at 16.35 keys on the non-KS version with no sales that low, 17.3 as the low end should work
Using all Killstreak tiers except for Professional because they sell for more
Taking Gladiator.tf stats past 30 days, rounding all values to the nearest 0.1 keys
(Non-KS) https://imgur.com/qaVgqLu
Sales:
1 @ 17 keys 14.77 ref, 17.29 ~17.3 keys
1 @ 18 keys
Buys:
1 @ 17 keys 33.77 ref, 17.66 ~17.7 keys
1 @ 17 keys 39.11 ref, 17.77 ~17.8 keys
1 @ 17 keys 36.11 ref, 17.71 ~17.7 keys
(Basic KS) https://imgur.com/nebVUsO
Sales:
N/A
Buys:
1 @ 19 keys 26.66 ref, 19.52 ~19.5 keys
(Specialized KS): https://imgur.com/bQMSJ2z
Sales:
1 @ 18 keys 17.44 ref, 18.34 ~18.3 keys
1 @ 19 keys 32 ref, 19.63 ~19.6 keys
Buys:
1 @ 18 keys 29.55 ref, 18.58 ~18.6 keys
1 @ 18 keys 29.11 ref, 18.57 ~18.6 keys
1 @ 17 keys 31.11 ref, 17.61 ~17.6 keys
Classies:
(non KS) https://snapshots.tf/snapshot/603b6aad0902fec4281f23ea Sellers: 18 keys, Buyer's: 16.35 keys
(Basic KS) https://snapshots.tf/snapshot/603b7a140902fec4281f54d6 Sellers: 20.49 keys, buyers: 17.4 keys
(Spec KS) https://snapshots.tf/snapshot/603b74990902fec4281f43bc Sellers: 18 keys, buyers: 17.01 keys
Conclusion:
Anything over 18 keys is gonna look high given the sellers at 18 keys on both Specialized Killstreak and Basic Killstreak, can include 18 though with a sale at that value. All sales above 18 were on a Killstreak version anyway
Buyers are only at 16.35 keys on the non-KS version with no sales that low, 17.3 as the low end should work
Taking 17.3-18 keys
https://backpack.tf/classifieds?item=AWPer+Hand&quality=11&tradable=1&craftable=1&australium=-1 - sellers down to 16.7 keys atm
They're up to 19 now with only one seller at 17.59
Buyers down to 14.82 and sellers down to 16.42, the current price might be ok for now