30k is a very good budget! Wife,3 kids,smaller lake and good skiing: you could look at older Prostar 205. Fuel injection,no wood,plenty of space,very nice ski wake,open bow,well within your 30k.You can beach a DD,just be more careful.Big swim platform for the kids to get in and out,more important you and the kids will enjoy skiing it way more then I\O for sure.Just the sound of the bullet proof V8 is reassuring,easier to drive for the wife and no trim to mess around for her.You may have a couples of seat skins to replace at that age but still very sexy boat for sure! Very solid construction too! Good luck!
Here's one to give you an idea...
You gonna have a dock or tow it every time?
https://www.ski-it-again.com/php/skiitagain.php?endless=summer&topic=Search&category=Boat_3Event&postid=65886