I'm not sure if the Victory worth $150 - that depends on what parts are missing. If it is something really important, like masts or rudder or something like this, it's not worth it.
Royal Lous, if it's 1/200 model, doesn't worth anything. Well, may be $10.
Soleil Royal and Pamir may be worth something, may be not, but I wouldn't buy it close to retail - I'd rather by it retail than possibly damaged. They are easy to find. :)
Now, the truly interesting, in my opinion, kits: Chebec and La Reale. Mind you, though, they are interesting to me, because I truly love the look of those ships; I don't know their objective worth. For Chebec, I would absolutely buy it for the price, close to retail; the ship, in my opinion, is great. Currently, Heller Chebec goes for $120+ easily on eBay, and it's impossible to find in shops, at least for me, at least for any reasonable price. I'd say, under $100 it's a bargain.
La Reale - also very beautiful ship. It can be found for as low as $90, may be even less; but it can go for as much as $120 on eBay, too. If price is lower, and you have money you can spend, I'd took it.
Oh, and as for methods of bargaining on eBay, "sniping" is not always the best strategy. Sometimes, it's worth to rise a bit the price of the item right from the start, from day one, so that "last-minute snipers" weren't interested; this way the final price, without last-minute "bidding frenzy", may be actually lower. But it is by no way a sure thing.
Oh, and sometimes you just get lucky. Right now, when I'm writing that, I've got two wonderful models for a song on eBay, really for a song, lost third to a sniper frenzy in the end and now waiting to see, if I'll be able to get the last one. :) I have a feeling that the same sniper who got the third one has his scope on this one too... But we will see...