This
Everbilt
1/4 in. × 3-1/2 in. Snap-Off Design Toilet Bowl-To-Floor Bolt Set
requires the whole toilet removed new ring flange and another $850? Pls let me know
Yes,
the toilet has to be removed to replace the bolts. Since your plumber quoted $350 for replacing the wax ring on your other toilet, expect to pay him $350 for this job because the wax ring *must* be replaced every time the bowl is removed. The $350 your plumber charges is for removing the toilet, replacing the wax ring, and replacing the hardware. Again, the toilet MUST be removed to replace the bolts, and we're assuming the flange on the second toilet is OK for the $350 charge.
Did you watch that video I posted above?
BUT! If he pulls the second toilet off to replace those bolts and finds the flange rusted out in the same way your powder room toilet was, then we know that your plumber will charge you $850 for this job. Unfortunately, there's no way to find out if the flange that holds the bolts down is good or bad until the toilet is removed.
You said you could call a handyman, do you know one? Or do you have a handy neighbor who could do it for a pizza and six pack? This is not a difficult job, only messy.
John
EDIT: regarding the bolts - they do not screw in from the top and attach to the sub floor or flange. The bolts are anchored into the flange under the toilet. The toilet is then lowered over the bolts and set down. The nuts are then threaded onto the new bolts and gently tightened down. Because the bolts are anchored into the flange, the toilet must be removed.
Here's how the bolts are attached: go to 8:25 of the video to watch the bolts being attached to the flange.