Hmm, personally I'd just use the store "Inquisitive" eyes before going after a Wendy or a Fallen Star. So much cheaper and I actually think nicer a lot of the time.
As far as quests go, firstly I don't tend to go after quests I think are impossible in the first place (eg. I'd love a Panda Hat, but nope). Once I've picked an achievable goal, I either take the determined route where I throw everything at it for a few months and try to raise money through vending/investing and such if I really want it, or I decide I don't need it right away and just wait until I accumulate some extra gold and find a cheap deal. The longest I've spent on focused questing is probably about a year for my Angelic Sash quest. I wouldn't want to go much longer than that, though. Too frustrating and I don't think any virtual item is worth that kind of effort (for me, anyway).
I was questing zodiacal since it came out. When it finally finished evolving and went up to 1mil+ I made a quest thread because I knew I'd give up on it. i had a lot of generous people come in and chat to me and some of them were really nice and donated to me >w< I got a lot of stuff off my wishlist and some gold. Then Chocolat Tiramisu donated Midnight Rainbow and 1mil to me gonk and I had enough to get 2nd gen. So, I got 2nd gen. And now I can move onto my next quest Sainte Ciel: Eros. Curse you Rosamund's Revenge! I could have bought it before you came out gonk
I tend to give up when I think..."Is this really worth it? It's not really nice. neutral". Also, when I change avatars, and I don't really have a reason to use it anymore. I actually might stop questing Heart X Mind because of these two reasons (and start questing Manslayer of Lalune + Solair? :'B)
When I'm hardcore about a quest, that sucker is getting done no matter how long it takes. It took a little under a year to get my Angelic Scarf, and a little over a year to get my OMG.
However, I'll definitely abandon a quest if I feel that the cost/benefit ratio changes too much. I was questing for Shibuya Nobody a while ago, for instance. It had been a while since I had checked the price, and I found that it had more than doubled. It only took a second to decide that the item was no longer worth the price, so I had no qualms about spending that gold on something else.
On the other hand, I had fancy quest threads and received donations for the A. Scarf and OMG. I was working on the Shibuya Nobody quest quietly, by myself. I may have reconsidered abandoning it if people had donated to the cause.
I find its easier to get what I want by not questing for it, because I can spend the energy I would have used on questing (and when I say questing, I mean doing more than just putting a "donate to me" bar in my sig, but like actually setting up a quest thread and keeping it alive, etc) for more gold-earning activities like BG, vending, etc cat_3nodding
For example, 2 games of BG will always earn you, at least, 1k, which might be the equivalent of four, or five, bumps in a quest thread, which means you'll probably make about 50g, if that, from bumping versus the 1k you'd make playing BG, so... You see what I'm saying? cat_rolleyes
Still, props to all those capable of achieving their dreams/goals through questing cat_wink
Usually, if I give up on a quest, it's because I became disinterested in the item. A lot of the time, I will fall in love with an item will make plans for how I am going to use it, only to later change my mind and find something else I like better. (Hopefully, something much cheaper). I add things to my wish list and prioritize one or two items, but because it takes so long to get certain items, I have more time to think about it, rather than impulse buying something that looks really cool, only to rarely be used.
So yeah, I don't really quest much, but when I do, those are the main reasons I quit.