Dragon Tooth
Dragon Tooth is a reliable form of Damage scaling that works excellently alongside the
Busy Bees. You get a lot more value when it's applied to multiple Small Weapons, which isn't too common with most Pyg builds.
The fact that it spends gold every time is actually beneficial. This counts towards the 50 gold requirement of
Bootstraps, giving an additional method outside of vendors.
A word of warning, as of writing this, the
Bootstraps may be bugged to not apply the upgrade/enchant if the
Dragon Tooth trigger is what would activate it. Keep that in mind so it doesn't accidentally go to waste.
Gumball Machine
Gumball Machine, along with the Gumball event, is a worthwhile way to help scale the
Busy Bees. Since they can't be upgraded through normal means, all of their power needs to come from scaling.
Gumballs may be minimal, but when stacked in multiples it can really make a difference. Plus, since this build requires only three purchasable items, it's a lot easier to have enough spare gold to justify their purchase.
Noisy Cricket
Noisy Cricket is a solid board-wide Damage buff for wider boards that can take advantage of it. It's essentially just a slightly better
Strength, but only applicable to builds with seven or more items.
Having multiple options of Weapon skills is great because you'll generally get much better value from a new skill over upgrading an old one. Just pick whatever gives you the most overall Damage.
Sharpened Steel
Sharpened Steel is insanely strong with this particular setup. By having multiple fast-acting Weapons that are all adjacent to each other makes it super easy to hit 100% Crit.
It's worth pursuing the Bouncertron PvE Encounter if you see it. Otherwise just try and pickup whatever common Crit Chance skills that are available to you.
Arms Dealer
Arms Dealer isn't quite as effective when Properties are the priorty, but with a strong enough Economy you can still make good use of it. At the very least it will gradually increase your Health as random Weapons are acquired.
You'll get a lot more mileage out of this skill during the early game when items are generally cheaper. If it's later in the day it's probably not worth it since Gold/Diamond items become far more prevalent (and expensive to continuously buy).