Can I set shipping rates based on order value? I'm trying to set up shipping rates the client used prior to Craft Commerce. So for example, if the cart total dollar amount is:

0.01-$35.00 rate = $21
35.01- $170 rate = $39
170.01-$275 rate = $44, etc.


is this currently doable or will the client have to switch to a per item or weight-based shipping cost?
Within Commerce Settings -> Shipping Methods you can set within the rules of that method, the 'Minimum Order Total Price' and the 'Maximum Order Total Price' and an associated shipping cost, so yes, it is possible to recreate your clients existing setup.