I know very little about Tammy dolls but this was what I could dig up:
Yours is the first version of Tammy according to this site:
http://dollreference.com/ideal_tammy_doll.htmlIt started in '62 and the new doll design was introduced in '64 so she was made between these two dates.
For a good condition Tammy doll with an outfit (the more complete, the better) most went for
at least $20 on ebay. Light blondes seemed to go for more, dolls dressed with certain outfits did too.
Speaking of which I could not find your doll's outfit! Is either piece tagged or at least look factory or do they look handmade? If they're tagged you may have a HTF outfit...
Hope this helps a little bit!