Investigate arb execution

[hdevalence]

Describe the bug

Look at the following output:

~/c/p/penumbra3 ((v0.66.0)|✔) $ cargo run --release --bin pcli --  q dex arb-execution --height 4645
    Finished release [optimized] target(s) in 0.28s
     Running `target/release/pcli q dex arb-execution --height 4645`
Scanning blocks from last sync height 4675 to latest height 4675
[0s] ██████████████████████████████████████████████████       0/0       0/s ETA: 0s
46.566735penumbra => 6.342551penumbra via:
    Trace                                                                                                                                                    Subprice
    4.801446penumbra =>   6.241878888888888889test_usd =>   5.617691penumbra =>             5.617691gm =>          7.02211375test_usd =>  5.61769penumbra    854.702mpenumbra/1penumbra
    4.801446penumbra =>   6.241878888888888889test_usd =>   5.617691penumbra =>             7.02211375test_usd =>  5.61769gm =>           5.61769penumbra    854.702mpenumbra/1penumbra
    4.801446penumbra =>   6.241878888888888889test_usd =>   5.617691penumbra =>             5.617691gm =>          7.02211375test_usd =>  5.61769penumbra    854.702mpenumbra/1penumbra
    4.801446penumbra =>   6.241878888888888889test_usd =>   5.617691penumbra =>             7.02211375test_usd =>  5.61769gm =>           5.61769penumbra    854.702mpenumbra/1penumbra
    4.256778penumbra =>   5.533811344444433872test_usd =>   4.98043penumbra =>              4.98043gm =>           6.2255375test_usd =>   4.980429penumbra   854.702mpenumbra/1penumbra
    4.98043penumbra =>    6.2255375test_usd =>                                                                                            5.602983penumbra   888.89mpenumbra/1penumbra
    637.261mpenumbra =>   637.261mgm =>                     796576250000000000wtest_usd =>                                                716.918mpenumbra   888.89mpenumbra/1penumbra
    5.617691penumbra =>   5.617691gn =>                     7.02211375test_usd =>                                                         6.319902penumbra   888.889mpenumbra/1penumbra
    11.868791penumbra =>  14.242548888888888889test_usd =>                                                                                12.818294penumbra  925.926mpenumbra/1penumbra

Expected behavior

The summary 46.566735penumbra => 6.342551penumbra seems wrong?