Rolleiflexes E are wonderfull, both in 3.5 and 2.8 and easier to repair than than the F's.
The lichtmeter was of the selenium type and measured from above the focussing lens.
On the E's they were not coupled, on the F's they were.
The verry late 3.5F Planar's were even better than the 2.8F Planar's.
If you want to go cheaper: get a Rolleicord Vb, they are good performers too.
I own a 2.8F that I restored about 25 years ago: a great camera and I got it by repairing and 2.8E cause the owner lost faith in the 2.8F .
Rolleiflex and leafshutter repair and prof.photographer