Yup! Everytime you blink it seems the price of postage goes up. This is an old post so the prices are more than likely outdated. You can always research the current prices & purchase a scale. They are $25 at walmart & are good for up to 3lbs.

http://forums2.gardenweb.com/forums/load/exseed/con101211287117.html

I forgot to add the link hahahah sorry

As a clerk at the post office explained, if there is anything besides paper in the envelop it is considered a parcel and the minimum price is $2.07 (I believe up to 3oz) Scale or no scale it is up to a post office worker to decide if your package is a parcel or a letter. And if you at it, at least get a tracking number. My last trade had to be canceled because I didn't get the tracking number and the package disappeared (Sorry europa13, such a bummer, it had mint cuttings).
If you don't want to use a bubble envelop, make sure your trader knows that. I got so many crashed seeds it won't make any sense to trade without a bubble mailer.
I'm still looking for people I traded with who got that dreaded postage due. Please let me know!