I think this board is populated by very knowledgeable people who really prioritize horse fit, and, thus, there are a lot of enthusiasts for wool-flocked English brands.
But, as I understand your question, you are looking for something that is good enough and that you can resell in a few years for a similar price. I am assuming that your daughter’s horse is a fairly typical shape and size.
I agree with the person who advised you that some of the more customizable brands are the hardest to resell–in part, because they ARE so custom-fit that you have to find the exact right buyer whose horse is shaped like yours and knows what they need. (And, honestly, if you are doing big h/j shows, they are not trendy in that market.)
I would vote French, in a fairly standard flap and panel configuration, and I would vote used in the <$2k price range. Most of the saddles come in various leathers now. Grain wears the best, so it is mostly likely to hold its value. I mostly ride in a Butet from 1997 that is in gorgeous condition, which is not an argument for that particular brand so much as an example of how something of similar age in grain leather can hold up. I am confident that, having ridden in this saddle for several years, I could resell it at no loss tomorrow.
I do a fair amount of monitoring the used saddle market for French models, and it is fairly rare that they trade for less than $1,200, even if they are pretty old and have obvious wear. But there is a lot of variation in the $2-5K range, which suggests to me that saddles lose value rapidly at those prices. Anything you buy new is going to lose value particularly quickly, especially if it is customized in any way. I would not buy a used French saddle that needs repairs other than new billets–those costs can quickly dwarf the purchase price. Even reflocking them is $$$$.
I personally do not enjoy CWDs, but I do not think they are going out of style so fast that they would be a bad investment, assuming that your kid likes riding in one that is appropriately priced for its condition.
Another option is just buying a quality saddle that is so cheap that you don’t care about reselling it. Some posters have mentioned older Stubbens and Counties. Those are high quality saddles that are often available in the three figures.
One more thought: I would never do this personally, but some of the high-end manufacturers have programs for children where, if you buy new, they let you replace the saddle annually for like $500 as your kid grows. That takes the trade-in process off your plate, but locks you into one brand.