76k Mile Transmission Drain and Fill - Change Filter Also?

I'm currently getting quotes to get my 76k mile GX460 transmission fluid changed out while its in the shop to get the engine oil changed. I'm not getting any clear info on whether or not I should have the transmission filter also changed at the same time. I'm planning on getting a simple drain and fill done on the trans. Also, the first shop quoted $600 for the drain and fill with a filter change, is that reasonable? Located in Houston TX. Just asking this community first to get a clear idea on whether or not I should go ahead and get the trans filter changed at the same time. Thanks for the info, it's much appreciated.