Welcome funmonkey!
To your question about the Daisuki Fan Club Pikachu. This card was made twice. Once in the DPt-P series (016/DPt-P) and once in the L-P series (019/L-P). 016/Dpt-P has a different layout and is rarer.
Long gone are the days when 019/L-P was priced at $100. Today $25 seems reasonable although with patience you can find it for less, even on ebay. On Yahoo Japan the card sells below 1000 Yen but then you have the fees to consider. Is it a good investment? Well, it certainly is a nice item to have for your collection but I wouldn’t expect you to make a big profit from reselling it in a few years.
Things are different for 016/DPt-P. Fair price is difficult to nail down because there are very few explicit 016/DPt-P sales. Indeed, I saw only one completed sale, on Yahoo Japan, about six weeks ago, very beautiful specimen, ending at 4200 Yen. So, if you can get 016/DPt-P for $25, go for it by all means. You might even turn your new acquisition into a nice profit by auctioning it off right here on this board.