Yes indeedy, Megan, you've found the salads. Amazoni Mantraps, and their cousins later on, the Jungle Lilies. Both are deadly to a young party. The clue is "...and they killed me before I knew what was happening".
For a low-level party, flamedrop is absolutely the best spell to use. Why? Because it keeps on giving. Cast it on a salad, and every second (or so), the salad takes damage and has its attack disrupted.
They can't fight back!
It may take a while, as Felix pointed out, but have your wizard cast flamedrop on each salad, and then keep on casting. The one thing you don't want is for the flamedrop to wear off...
And Radek, I mentioned trying to use the drawbridge as a weapon. I haven't done it yet, but the Den is getting so desperate to get rid of the remaining salads that they're willing to try almost anything...
Fire bombs are also effective against the salads. I wish I had some...
As for money, you've got a couple of options. You can put all the like items with one character, because one ID will identify all the like items. For things like arrows, potions, gems, bolts, shurikens, and throwing knives, always keep one in inventory. When you pick up more, they get added to the already-identified one, and you get free ID. Just make sure you don't give an identified item to someone with the same item unidentified -- then they all become unidentified
You can also use arbitrage, which involves your warrior going into the back room of the warrior guild to buy +1 arrows, and then selling them in the front room. There's quite a profit in those things... There's a better markup on Takekatsu arrows in the Bushi guild, so if you're a bushi guild member, that's a better place to arbitrage.
Good luck!