From the GameFAQs inventory guide:
Quote:
Certain items don't show up in Vincent's shop until you do a certain amount of
buying and selling in your game.
You can check your current point total by pressing R at the main shop screen
(Buy/Sell/Item Display). For every purchase you make at any shop, you earn 10%
of the purchase price in shop points. Sales, however, yield varying amounts of
points depending on the mode in which the sale takes place: 100% over Wi-Fi,
50% over Wireless, and none using Vincent's shop.
The following items are unlocked by earning shop points:
1,000 - Powdered Milk
2,000 - Miko Dress
3,000 - Silk Negligee
5,000 - Feather Gear
10,000 - Paludamentum
20,000 - Spiked Mail
25,000 - Magical Ticket
30,000 - Holy Claymore
50,000 - Record 5
Note that this information comes directly from Konami's Hints page and has not
been thoroughly tested. The page, in its original Japanese, can be found here:
http://www.konami.jp/gs/game/dracula_ds ... index.html
I guess it's 20k for Magical Tickets and 25k for Holy Claymore, but since the ingame timer stops on Wind's quest screen and Vincent's shop screen, you really only have to worry about how many trips between Wind and Vincent you need. 5 x 9 Blessed Rings gets you 562500 gold, which should be enough to buy all the stuff you need. I don't think four trips would be enough, but I haven't bothered to look into that. To get your 25k shop points, just buy all the stuff on the list and then a Master Ring, or Feather Gear, or Spiked Mails ... there's enough stuff to choose from, just don't forget to sell it back to Vincent.