MSI , Gigabyte, EVGA and ASUS with or without backplates cost about the same , all depends what store. When I was buying my Gigabyte then it was about $20 cheaper than EVGA SSC, MSI Gaming and ASUS Strix while only ASUS from these 3 had backplate. Right now there is available lower Gigabyte WF3 ( not G1 ) without backplate and with slightly worse cooler for about $30 less but I'm not sure if it's worth the difference.
Free backplate is a nice thing but competition in similar price was giving backplates and also better power section and higher power limits so card after OC won't throttle. Exception from these gaming series is maybe ASUS which has backplate but power limits are almost the same as in EVGA.