Any toploader that doesn't have a spin brake is required to lock the lid for safety reasons. Washer mechanisms nowadays have been changed such that very few have brakes. Most of them lock for the entire cycle. A few may lock only during the spin periods.

One that I know doesn't lock at all is the Speed Queen TC5, which still has an old-style mechanism with a spin brake, but it's above your budget.

Other brands & models ... you'd have to question the sales people or manufacturer via phone reps (and neither may have accurate info without actual hands-on use of the specific model) .... or get info from people who have used specific models of your interest.

I don't really understand, "run the detergent cup under the water and to Fill the washer with a load" but the LG WT7300CW ($698) and WT7100CW ($719) allow you to pause the washer thereby unlocking the lid (to add clothes) during which time you could presumably do whatever you want.

Thank you!! We are going to check this one out today!

I don't know how you feel about agitators, I like 'em and the model I have has an agitator! Had one without it once...for about a week.

Also the one I have is a 5 cu ft. It's HUGE but I needed to get a larger washer to get the water I wanted and to be able to wash a king size quilt.

I thought I was the only one who wanted a washer that didn’t lock! I add items now and then and I also do a lot of hand laundry that I just like to spin lightly and re’ove. Luckily my current to load washer does not lock.

Dakota01, any toploader with a lid that locks can be unlocked to add an item by pressing the Pause button, then Start to resume. Typically pressing and holding the Start/Pause button for several seconds cancels the cycle.