I’ve been thinking this one over for a bit. Ponywear in general tends to be less popular, and it doesn’t have as many price fluctuations as some of the ponies do. “Nirvana” ponywear is a very niche market, and the big money is usually in the super rare or unique stuff(Japanese, Indian, etc). It’s likely that the market for your stuff is still about the same as when I last bought mine. You’ve got some of the basic outfits there, so nothing exceptionally rare.
I’d say the Neon Lights outfit is the cheapest of the lot, both due to the card condition, and it being an unpopular outfit. The other two outfits are both very easy outfits to find from other countries loose and MOC, so they’re probably not going to bring in a whole lot more. I think they are some of the more common Italian outfits.
*Personally* if I was in the market for those outfits, I’d pay $20ish for Neon Lights, and $30ish each for the other two. I might be willing to go up about $5 each if I had to. Again, that’s just me, but hopefully that gives you some idea. I should triple check my collection to make sure I don’t need any of them:p