Double colorless was a league promo a month ago... they're reliably selling for 1-2 dollars, especially the old ones.
A 1st edition Fossil Recycle sold last month for 99 cents with free shipping. An EP RH one goes for about $4.
Elm's is less than a dollar, unless you want one of the Professor Program ones.
Pokemon Collector is rather expensive right now, they're fluctuating between $4-10. (Most are $6+, though, you've got to be lucky/patient to get it lower.)
Rare Candy, even with the nerf, is still going between $4-7.
Fisherman is going for $1-3. A reverse holo one just sold on eBay a couple of days ago for less than $2, including shipping.
Catcher is going between $6-8. Reverses are $10+.
All prices off eBay completed listings.