What zones give valuable items from foraging? I'm still F2P until I get higher levels, so those zones would be preferable, but the others would be interesting for future reference.
Err, what are you trying to accomplish? If there's specific recipes you're targeting then yes, there's zones or expansions that have the relevant items to forage. If you're trying to get stuff to sell, don't waste your time with foraging.
rare forage items are a nice extra when you are killing in a zone. Most of them can also be obtainable via killing which will result in much higher return of items usually. Going to a zone just to forage for profit is typically a horrible way to make plat unless you plan to do it illegally by automation or just have an extra toon you want to hit a macro on while actively playing on another account.
To my knowledge there are no foraged items that are particularly valuable relative to how much you can get by farming mobs.
Morning Dew usually sells for a few plat, which you can get in Greater Faydark. But most of the stuff isn't really worth the time invested unless you just happen to be there doing other things anyway.
There are only 2 expansions with zones F2P cannot get into so that should not limit you much. Look under /barter and see what players are offering for forage stuff. You will get ripped off on some stuff but might make a little plat on others. Like people have said there are easier ways to make plat. Do the dailys for all levels you can get - they award plat and armor. Sell the armor to the npc for 2-9 plat.
Deadly... if you click for hours to get one... Nice idea, had that before, was very disappointed... Found a zone where you have decent success?
Go to Stratos and forage Primordial Leaves, Primordial Fruit, and Primordial Legumes. Those all make high end food and drink and should sell well in Baz.
Fruit is foraged in most zones. It is sought after for making Misty Thicket Picnics. Griffon/Aviak eggs are foraged in North Karana and Butcherblock Mountains respectively. Oak Bark in Kithicor Forest (for Halfling Cultural). Sylvan Berries are from Lesser Faydwer (and I think you can forage Morning Dew there too). Marr Cherries are from Ocean of Tears. I think in the LFay LDONs, you can forage Gargoyle Granite and Spider Silk...but my memory is hazy. Natimbi offers Raw Dark Matter (I think). Bamboo Shoots in Stonebrunt Mountains. Seahorse Roe in Erud's Crossing. Mostly what I have listed is for tradeskilling. Nothing particularly interesting or highly sought after.
If your on xegony my buyer is currently looking for most of the stuff recently mentioned. I am paying pretty decent plat too for wild crimson berries and crimson berries I think its foraged in any luclin zone. Paying 100p and 150p per I do believe. Not crazy sick prices but decent plat for a fairly common forage. I would be buying a lot more of the common tradeskill foraged stuff but until I actually run across the recipes on my quest to 350 I don't have an idea what and how many I need of everything.