you are correct the mag is the only difference here is what Buds says about pricing From Buds “Our website updates every 20 minutes, 24/7, with our current inventory and replacement cost. We do not price our guns manually based on our cost in each, rather we use a live download from manufacturers and distributors to set our price based on our current replacement cost. As our cost changes, the corresponding website price of each make/model will change up/down accordingly.
Although our profit margin remains unchanged, our advertised prices will change frequently, sometimes several times per day.”

Dirk, the only difference is the magazine capacity Sir. Buds prices are tied to stock level and there are more of the 8407 in stock which makes the price a little higher. Cheers and stay safe Sir!