Hi, I'll add that sometimes you can find marked-down 3-booster blisters with a promo card in it, if marked down by 15%-20% you will usually make a profit from the packs either through trade or by selling to an outlet like T&T.
And some of the promos are fun to play with as well. My favourite X&Y era card is Celebi XY93 (but is only really good in expanded format)
I also recommend you take care in choosing the right protection for your cards and commiting to being the best collector you can be before you allocate money to the card budget itself.
Buy a good portfolio like the Dex Protection 9 or Ultimate Guard Xenoskin
Buy good sleeves like KMC Hyper Mats or Dragon Shield (may also want to get KMC perfect size sleeves for double-sleeving)
Since you are just starting out, you can maximize your collection's potential by prioritizing protection from day 1.
You may look at Ultra Pro and think "these are $5 cheaper than the KMC Hyper Mats and have 20 more sleeves... They can't be THAT much worse... Right?"
But you're wrong, they are. They're even worse than the price difference suggests.