Fridge trailer advice

Basically I am crunching the numbers on a new business idea and any experienced advice would be much appreciated. I’ve been thinking for some time about purchasing a refrierated trailer to hire out, specifically a schmitz or krone with a twin evap carrier motor.
Iam a fridge mechanic by trade so I have that base covered, however does anyone know the typical price for a chassis maintenance package?
I have a hgv license and somewhere to store the trailer if its not being used.
Anyone hired a fridge trailer before and have previous experience?