The lead offer on this page is the 10% off sitewide promo at Hobbymate Hobby, presented as the promo code at the top of the page. That code is best for general purchases across the store. There are also specific product codes (15% or 10% off a Jumper T16 gimbals protector), a $10 off charger code, a selection of items reduced by 33%, and individual item deals priced from $3.90 up.
Very small buys under $10: If you are buying a single low cost part such as a $3.90 prop, using the 10% off sitewide promo reduces $3.90 to $3.51, a saving of $0.39, so the sitewide code applies. The listed deal prices (for example items shown at $3.90) are already that price, so the code only helps if the deal item is not already restricted from offers.
Single charger purchase around $99.90: The HOBBYMATE D6 Duo Pro charger is promoted at $99.90 as a deal that cannot be used with other offers. Compare that with the $10 off charger code. Using the $10 off code on a $99.90 charger drops the price to $89.90, saving $10. Using the 10% sitewide promo on $99.90 would take $9.99 off, leaving $89.91, saving $9.99. The $10 off charger code leaves the lower total ($89.90) and is the better choice for this item, provided the product is eligible for that charger code and you do not try to combine it with the deal price.
Buying a selected RC model or accessory that is on the 33% off sale: The 33% off is applied to selected products only, and the title price will already reflect the reduction while stock lasts. For a selected product that normally costs $120, 33% off reduces it by $39.60 to $80.40, saving $39.60; that beats the 10% sitewide code, which would save $12 on a $120 item. Use the 33% off sale price for items that are explicitly in the sale.
Buying the Jumper T16 gimbals protector: If your cart contains that specific gimbals protector, the dedicated 15% off code for that product gives a larger item discount than the 10% sitewide code, so use the 15% product code. The product level 10% code for the same item is weaker than the 15% code and also cannot be used with other offers.
Newsletter or first time signup: The newsletter signup is separate from the promo codes. If you have not signed up and the newsletter offers a first time signup discount, use that only for low spend first orders, but do not treat it as the page lead offer.
When choosing between options, run the math on the actual item price and take whichever leaves the lower total. Product specific codes and the $10 off charger code state they cannot be used with other offers or with deal prices, so pick the single best offer for that product rather than attempting to combine the sitewide code with item deals.