A few short notes on the value of portable typewriters as seen on my websites.
If you are reading this page, it's pretty likely that the only reason you've entered my little corner of the internet is that you're trying to get a value for a portable typewriter -- either for insurance purposes, or to find out a good selling price.  The answer is:  It varies.   More detail:  It varies enough that no one list can be made to cover it, and also varies enough that I cannot possibly answer every e-mail about valuation. 
"But why not?  All I want is a general price range!"   Ok, well then I can tell you that for a postwar portable typewriter, you can find appropriately priced machines in very good to mint condition between five and two hundred dollars.  Some particularly rare machines, in particularly rare models, in particularly unusual colors, can go higher than this.  If you can't find anything about your machine on my site, then it's either REALLY COMMON  or else completely unknown.  The odds are quite against the latter --- which pushes the likely price for your machine rather further down the scale. 

The vast majority of portables out there are actually, honestly worth something in the ten to forty dollar range.  You could have a rare enough machine which isn't in great shape or even working, which could be at the top of this range.  You could have a very common machine made in the hundreds of thousands which is in absolutely mint condition, which would be at the bottom of this range. 
The machine at left is in mint condition, working perfectly and missing no paint, with no chips and no replacement parts; all decals are intact, and all letters on the keytops are in original condition.  It's worth about twenty or twenty-five dollars.  They made LOADS of 'em.
The machine at right is newer, but is exceedingly rare; only two are known to exist.  The machine was a total failure in the marketplace.  I'd value it at about thirty to forty dollars -- that is, if any collectors actually spot it on auction and compete to be the third known owner of one.
Here's a little Remington Travel-Riter.  If your machine says Remington, Royal, Corona, Smith-Corona or Underwood on it, the chances are pretty good that you're looking at the ten to thirty dollar range.  Made in USA usually means "made in hordes."
Why won't I do appraisals?

1.)  I can't examine the machine.
2.)  If I can't see it and operate it, or determine the exact condition of the mechanical parts, then any valuation is meaningless.
3.)  Most people will pay their own value for something -- which can be quite high if they want it enough.  On the other hand, if everybody already has one, or doesn't want one, they'll pay nothing -- they won't even take it as a gift.
Ninety percent of the requests I get are for the usual ninety-nine percent of the machines ever built.  Those that are exceedingly rare remain so; I detail these on my site, in various articles.  If you have one of these machines that's considered either rare, or desirable, or both (like an Alpina, a Rooy, a Voss, or others) then you might get some money out of it, if it's in good enough shape.  Look around my site and determine if you have a rare machine, or one I show in detail.  Chances are good that if I have a really big send-up of a machine, you might turn it for some bucks.  If I don't, chances are good you won't. 
to search further for your machine.