A lot of sellers on AliExpress already do free shipping. There are SO many sellers there selling the same stuff, you can just deal with the ones that do free shipping. I don't see how what you want is really neccessary.
I'm pretty sure you can't set it as an option in the current plugin. You'll have to request it as a feature in a future release. But it sounds a bit messy to me considering we're using multiple sellers. You'll have to do it manually. But like I said ... with so many AliExpress sellers offering free shipping ... why bother? Why create extra unneccessary work for yourself?
I'd say that store wide Free Shipping on EVERYTHING for ALL orders would be a bigger incentive to buy than just free shipping when you spend $50!
But I'm new to this plugin .. so what do I know? lol
I agree. Artificially creating shipping/handling costs, and even giving "free" shipping triggers shoppers into buying more.
After all, a buyer feels like he's saving money by buying more items.
Even if they just spend an additional $5 to cheat out of the $4,95 shipping costs, it's a good deal.
Your net margin might be slightly lower due to the purchase price of the $5 item, but your buyer will feel like having gotten an awesome deal.