Why would you want to buy a VFD from Amazon, and for that matter eBay? When it comes to VFD's it is a garbage dump of 3rd party sellers with no post sales support. These days most of the VFD vendors that sell on Amazon originate offshore. You might as well be buying from AliExpress. I get sick and tired helping people that buy Lapond, Vevor, Mollom, Mysweetie, Zhong, Shzond, Rattmmotor, SZCY, HKS, DPS, Blah, Blah, Blah VFD's and then complain about not being able to read the translated manual, let alone getting the VFD to work. If it is too good to be true, then it is most likely is crap. You shouldn't need to up-size a VFD if is is designed properly, most of these VFD's have internals/terminals that are way undersized for the supposed current levels, and ironically there are now Huanyang copies that are even cheaper and shittier. There are many mainstream VFD dealers that sell consumer level VFD's that will work well and they provide support pre/post sales, such as like Wolf Automation, Automation Direct, Drives Warehouse, Motors and Controls, etc. Teco, Fuji, Hitachi, Lenze, Yaskawa ... have very good entry level VFD's that are reasonably priced, have readable manuals, that will work out of the box and last a long time. If you buy your cheap VFD from Amazon from a noname dealer, what do you expect to get?