It seems obvious that A better way to purchase images should be closed as "asking for a list of recommendations."
But what about Font management tools for Mac?
Seems like the same idea, even if the second one is phrased a little more tidily.
I've seen loads of flavours of this debate on where to draw the line around open-ended endless lists in various stackexchange sites, and the rule of thumb that seems to work best everywhere is, "Is there a criteria which answers can be judged against?".
It's within the line if you can look at an answer and think, before hitting upvote, "How well does that meet the criteria of the question? Is it closer to solving the person's problem than that other answer?". It's beyond the line if the assessment is no more than "Yup, that is indeed another stock photo site".
Ultimately, the reason open-ended discussion questions are bad is not because people don't like open-ended discussions (people do), but because, with no real criteria for judging answers against the question and each other, upvotes mean nothing more than the number of interested people to see that answer since it was posted. Likewise, because they can never be solved or complete or "answered", an answer being "accepted" usually signals nothing more than "First answer the asker saw that he/she quite liked for some random reason, e.g. it was longer than the others or the answerer had a cool profile picture".
So questions without criteria get closed, not because people want to get in people's way or spoil the fun (I hope no-one does!), but because they are actually a little bit damaging to the site - they muddy the meaning of two really important pieces of what makes the site work.
If there was a criteria, however, you could imagine it working and upvotes and accepted answers having meaning. For example, "Are there any stock photo sites that are reliable for quality high-fashion imagery?", or "Stock photo sites with tasteful (cliche-free!) images for corporate design?", or "Best source for stock photography of men with dog's heads wielding axes next to cars?".
The asker would probably need to give some more detail on exactly what they are looking for, and why they aren't satisfied with what they've seen, and the correct answer might be a disappointing "Actually there isn't one that's reliable for this, and it's unlikely that there ever will be because [fact about how stock photo sites collect content]. Just use a mix of several good general ones, such as ...", but that's fine, the important thing is, judging the answers to these would mean something.