You know, I disagree with the whole Yu-gi-oh being so much more expensive of a game to play. Sure, if you want to build the absolute best deck, it will cost a lot of money. Remember that LBS with the Lati@s* was really expensive to build too.
I just recently got into Yu-gi-oh, and boy did I spend a lot of money on it /sarcasm. I bought some cards when the first set came out, back when there were many lackbuster monsters. The game has changed so much, and most of those cards are stupid. Thankfully, around 3-4 years ago, I bought 2 preconstructed decks at a Wal-Mart. Yu-gi-oh Pre-Constructed decks own Pokemon Theme decks SO MUCH. The Pre-Constructed decks often time have below quality monsters, but make up for it by putting in many good traps and spells. In Yu-gi-oh, spells and traps can often time win you more games than the actual monsters, especially if you don't have the money for all the best monsters. So having constructed decks come with them was just awesome. I recently bought another pre-constructed deck, and it came with a whole slew of great cards too. I combined the 3 decks, threw in a few cards from the first few sets, and have had a blast playing people and being competitive. Total, I think I've spent around $30.
You could NEVER do that in Pokemon.
Try going out and buying three theme decks (even the same) and building a semi-competitive deck. Decks don't run without staple trainers like Celio/Bebe, Basic search, pokemon retrieval, good draw (mama's concern doesn't count), etc, etc. Even then, you have to have special energy like DRE/Scramble for many decks. And then let's look at the game right now. Most competitive decks can't even beat the popular decks right now. What are the chances that a new player will even be able to stand up to a decent deck right now?
I see it all the time at the league I go to. People build decks by buying packs and theme decks. I bring a decent, yet nowhere near the quality of competitive decks, and just walk right over them.
Sure, I won't be able to go to a Shonin Jump tournament and do well, but I can at least win some games in Yu-gi-oh after spending a little money (less than $50). Many people couldn't do that in Pokemon without having to buy each card by itself online.
On the topic of where to buy Pokemon cards...buy Japanese cards. They are cheaper, you get more out of them, and they look cooler. Seriously, I don't see a single reason for people to buy english cards right now. You aren't guaranteed a foil, or even a decent rare (that isn't reprinted 3 times). Even when you spend $80+ on a box, you end up with a few foils, and maybe a lv.X or two.
I recently bought 4 boxes of DP4. It cost me around $270 (after $50 shipping). I pulled 11 lv.Xs (2 Glaceon, 1 Leafeon, 2 Garchomp, 2 Honchkrow, 2 Gardevior, 2 Cresselia), 80 foils (20 packs * 4 boxes * 1 foil GUARANTEED in every pack), a huge amount of Claydol, Pachirisu, Gardevior, etc, etc, etc. I was ecstatic over what I pulled, even though I pulled 1 less lv.X than average. How many lv.Xs would I have gotten in the ~3 boxes I could have bought of english cards? 0-6? I mention 0 because I've seen boxes end up with no lv.Xs. How many foils? 33-36? Look at the difference in numbers.
Sorry if this was a little long. It was more of a combined rant on topics.
