Yes. A thousand times yes. You NEED RPG Maker VX, regardless whether or not it's commercial.
Poor Celianna... I've been watching people struggle with this concept throughout your thread and all I can say is that you're a saint. I've met nuns with less patience. Thank you very much for all your hard work, both on the tiles and off.
For those who still have trouble grasping why VX is needed even if you have VX Ace, it's because many of these tiles are based on the original VX tiles. When you buy a copy of an RPG Maker system, you buy the licence to use the data contained within as well, including graphics, music, etc. However, you only get the licence to what is contained within that particular version, thus owning VX Ace does not mean you own any rights to anything contained within the original VX. Celianna is not being malicious or petty, just respecting the legal limits of what she has created based on the work of others. She gets no benefit from limiting you to owning the original VX (as far as I'm aware, though there may be some sort of referal program, I dunno, but it's kinda beside the point anyhow), she simply doesn't want you to be taken to court for using images you do not own the rights to. Chances are she would also be pulled into the fray for providing the materials and if it became too big a problem she may even be forced to no longer openly and freely distribute these resources to us, at least not without first vetting each and every recipient to ensure they have VX.
Some of you may be wondering why she doesn't just base her work on the tilesets contained within VX Ace. Afterall, that seems to be what everyone's buying these days. That would move the problem but not fix it. A lot of people still use XP, 2000, VX, etc, and those people would be subsequently locked out too. Then a new version of RPGM would come out, and those new people would be upset at the images being restricted to them too. No matter what tilesets she bases her work on, the same issues come up.
Then there's also the possibility of not basing any of her tiles on any of the tilesets included in any licensed material, but doing tiles from scratch is such a bigger job and it doesn't make the current tiles any less bound and she's already regularly doing other work.
We have a talented artist here who has given us a lot and the VX restriction is not her idea nor her fault, it's just simple fact like the colour of the sky. We, as a community, should really be thankful for the free resources provided to us. If you can't afford to purchase the rights to use the VX materials then you really haven't lost anything that you had in the first place. If you can get VX or already have it, then good, again there's no real problem.
PS. I apologise if I've overstepped my bounds talking for you Celianna, I just wanted to save you the effort of explaining yet again. I've been a subscriber to this thread for a very long time and this question has come up sooo many times...
thanks. 
