Depending on the nib that was on the pen, $9.50 US is a good to great price. Any recollection as to what the number on the nib was? If it was a 1xxx or 2xxx series, the price is good; but if it was a 9xxx (particularly some of the more exotic ones) the price is phenomenal (I've seen nib units for sale -- and have BOUGHT nib units -- for more than that (and yeah, that was just for the nib unit; I got lucky at the Ohio Pen Show last fall and got a 9048 (Flexible Fine) nib unit for $10. Crazy rare ones like 9312 (Italic) will cost way more than that (I've only ever seen one for sale in six years of searching eBay, and only seen one that someone actually owned). And the super rare lines, like the 3xxx ("Sunburst") series and 8xxx nibs? Nosebleed prices.... I saw one 8440 (Superfine/Cartography) nib listed for $85 and that was relatively inexpensive... (and no -- I'm NOT kidding...).
My understanding is that Esties are actually pretty easy to repair yourself, and if the nib/feed is bad it is often easier to get a replacement nib unit (the joy of Esterbrook pens is that the nib units are interchangeable).
I did try to fix the nib on one pen I got a few years ago on the bay of Evil (because it was literally bent into an s shape when you looked at it in profile) by taking a couple of pairs of jewelers' pliers to it -- on the grounds that anything I did wouldn't bork the nib any more than it already was.... Of course, then a couple of years later I found one on an SJ in the wild for less than I'd paid on eBay. Go figure.... And in fact, I had three different nib people look at my hack repair and tell me to just toss the nib unit in the trash and get a replacement one, even before that second 9128 nib came across my path....
But if you send the pen out for repairs it shouldn't cost anything like $100. Not on an Estie lever filler. A new sac will run a couple of bucks. A replacement lever will be five or six bucks more. Figure probably $20-40 for the repairs, depending on who you send it to (vs. the time you spend trying to do it yourself) plus shipping.
Ruth Morrisson aka inkstainedruth
"It's very nice, but frankly, when I signed that list for a P-51, what I had in mind was a fountain pen."