Been there, so here's what's inside. Personally, its not worth that much to specifically visit, unless you're looking for something specific in Jusco. Trip from JB Sentral bus station (look for signs saying Jusco Tebrau or ask to be sure before paying, fare is RM2.50). Travel time is around 35 minutes one way.
Going back, have to cross via an overhead road, as you cannot cross the street to go to the opposite bus stop (from where you alighted). Fare going back to JB Sentral is RM2.50 as well.
Outside the JUSCO grocery, with the car park, there are taxis you can ride. However they are bloodsuckers, I was quoted RM30 from there to KSL City Mall (that trip is shorter than JB Sentral). No way man. Maybe RM25 is forgivable since I read the coupon taxi from JB Sentral to Jusco Tebrau is RM21++, and that is JB Sentral already, not KSL!
For the bus, actually you can pay RM2.40 as that's the exact fare. However they just disregard the RM0.10 change if you don't pay exact.