For my Kraton and Rustler I use USPS Priority Cubic via Pirate Ship. With a tight 12x10x8 or similar box, most of mine land around 14 to 22 bucks. If the rig is heavy, UPS Ground sometimes beats it. I pull the wheels and body, zip tie the chassis to a cardboard sled, then bubble wrap so it can’t rattle. I ship LiPos separately by ground. Scheduling a pickup saves a trip.

Different scale, but when I moved a full-size car, I used A-1 Auto Transport and it was painless. Instant quote and live tracking helped a ton.