It all depends on you honestly. If you are looking for a female yb and the one offered is a pretty good example of the morph and the person offering it has a good rep or is someone you trust then it could very well be a great trade in your favor. To many variables honestly. To me if I liked the yb and wanted one anyways then I would do the trade if I did not already have plans for the spider female... That is unless I have a yb male then no need to trade I can just make one and if I have a male spider then no need to keep the female that small because again I can just make another. See variables lol.