
Posted: Sat May 25, 2013 11:33 pm
Hi there, I've bought quite a few myself.
eBay is indeed a mixed bag, but their "always side with the buyer" policy really does give you a huge advantage. I must have bought eight or nine Curtas on eBay, never a problem, and some I did indeed get fairly cheap, through luck I guess. But there's really no such thing as a really cheap Curta, unless you find one at an estate sale or something. Anyone who Googles, "Curta" will quickly find what they're worth.
Jack Christensen has, or used to have, a dozen or so for sale - he fixes them, so the ones he sells are guaranteed to work, which is a comfort. But Curtas are by design tough and durable - every one of mine works perfectly, without needing a servicing (I've cleaned and lubricated a couple but that's all). Jack's Curtas are quite a bit more expensive than even the eBay Frenchman's, whether the added cost for the guarantee is worth it is up to you.
http://home.comcast.net/~timewise1/curta/curtasforsale.html
I'd aim at a Type II for $700 or a Type I for $800 (the all-metal ones maybe a little more). Anything $100 less than that you're doing well. More than $200 above that, unless it's an unusual variant, you're paying too much IMO. Best of luck guys.
EDIT: Prices are for excellent-to-mint condition machines, per the ratings scale on the website above. Beat-up or repaired machines would be worth a lot less, but then you have to pay $500 to get it fixed, not worth it IMO.