If your kids are anything like my DD10 she is Pokemon crazy.
We usually pay about $4 for a pack of cards (10 to a pack I think). Toys R Us had them a few weeks ago, buy 2 get 1 free, you may want to watch their sales to see if they bring this offer back.
I was also able to get last years Holiday collector tin with about 30-40 cards I think for about $12 online in the TRU clearance section w/ free shipping about a month ago.
The best way however, we have found to get cards is off of E-bay, and yard sales. She only gets "new" ones for special occasions, Holidays, or when she uses her own allowance to get a pack, so she wasn't getting very many.
For her birthday however, I bought a lot of about 2000+ off of E-bay for around $80 with shipping.
The best way to do this without getting ripped off is look at the auction description, and look for someone selling their kids collection that they don't want anymore. Many dealers will get these huge collections and look through them and pick out all of the good stuff and sell the junk. Don' t buy from them.
The mom's like me who don't know a Pikachu from a Warturtle
, are the one's you need to watch the auctions for. We got a great deal doing this. My DD got lots of Holi-foil (I think that's what you call it), and even cards in other languages like Japanese, Spanish, and I think French. She thinks these are just the coolest ever
. She says that there are alot of really rare cards in her collection. She reads up on all of this stuff, I don't understand it, so I don't try.
I also like to go to yard sales in the summer, and I have found her several deals that way. I got a locking Pokemon tin full of cards, about 800 for $5, a Pokemon tin with a window in the top with about 500 cards for $3, and several times I have found zip lock baggies of cards holding anywhere from 50-200 cards for $1-$2.
However, DD does not tournament play, or collect certain series, hers are mainly just to collect and look at, as long as they are pokemon she doesn't care what series they are from. I got her some binders with card holders made for baseball cards, and that's what she keeps them in. She has 4 large binders stacked full of her collection, and another full binder she uses as her trader cards and the cards she plays with when her cousins come over. She saved some of the double cards from the lot for this purpose. The other doubles she had (around 800 out of all the ones I had purchase for her over the last year), she sold on E-bay for about $40 to get a little money to, of course, buy more cards. I swear she's addicted.
If your kids want to tournament play, that is a whole other thing, and I can't help you there. I can't even say the names of 90% of these things so I wouldn't even know what rules you go by to actually play.
One other thing since you are new to this that may help you. Just because the cards look the same does not mean they are doubles. I thought my DD was going to make me write this 100 times.
She nearly died, because I was helping her go through hers one day, and I told her she had too many alike and she should take some out of her binder and make room for others. I started to remove some and she literally dove over the bed and grabbed the binder like I was killing her child or something
. Apparently each card has a serial number in the bottom corner, and if those are different, even if the card looks the same, it is NOT, and I repeat NOT, the same card. Believe me, she made sure I understood that.
Just a little FYI, in case you run into the same thing.
, and thinks Pokemon is stupid 
sad2:her words), and her little brother is too little to play, however she has started training him. He runs around the house screaming, PI-KA-CHUUU!!!
It is great because they will all be a total surprise.
