A general rule I use is the repair item has to be $50 or less. If a motor, heating element (electric dryer), or a timer is bad it is questionable as to repair. I try to salvage these items from other dryers and use them for repairs to keep the cost down. GE electric dryers use a heating coil that is replaceable for a decent cost but the front bearing support for a GE units is a piece of junk . Old Maytags and Whirlpools are the easiest to work on and low cost parts are plentiful on E-bay. The old rotary timers are something are sometimes a problem area on these old units. The small 110 volt motor wears out the plastic gears inside its housing. I salvage these as much as I can. If a gas valve is in need of repair and a used one is not available the dryer is pretty much scrap as the valves are very expensive as new.
Hope this is of value to you.