Really Good Soft Starts are not expensive. $245.99
Hyper Engineering | Home
https://shop.gentekpower.com/collections/sure-start-ac-soft-start-ss1b08-16sn-ss1b16-32sn-hyper-engineering
SS1B08-16SN for up to 3 Tons
SS1B16-32SN for up to 6-7 Tons
They also make 120VAC units for RV units.
And 3 Phase units. They work for 50 or 60 Hertz