Random Ebay lots like that usually aren't a good deal. Those sorts of things are mostly put up there with the intention of parents buying cards for their kids. There are, of course, exceptions, but generally speaking, I don't recommend Ebay lots to anyone.
Buying cards is quite a bit different if you're collecting or playing. Players will want to focus on building up good playable cards (trainers and Pokémon), and getting into playing serious can be on the pricey side (especially if you're starting from scratch), so if you want to go this route, do some research, and check out some of the threads in the New Player forum. If you're just looking to play a fun game with friends without getting close to the competitive side of things, you may want to pick up a theme deck or two; they're typically about $12 each in the States and will be able to get you playing the game quickly and easy, though those decks aren't really good for anything more than casual play.
You have a bit more freedom with collecting. Depending on what you want to collect and what your plans are, you can buy singles, or even packs for a particular set that you like. If you'd like to try and complete a set, usually buying a booster box is a good way to start that, though that's quite a bit out of your price range. If there's a certain Pokémon you'd like to collect, sites like Troll & Toad and Collector's Cache sell singles from current and old sets. Tins and Promo Packs are also nice in a way because they give you promo cards in addition to packs, and the tins are nice for storing your cards or other small things in. Tins are usually my "go-to" item for a casual TCG purchase.
It should be noted that buying packs is usually less of a good deal than buying singles (your changes of getting enough good cards to match the after-market value for each card to the pack price are slim), but buying packs is a lot more fun. Even as a semi-serious collector, I love buying and opening packs since that's where a lot of the fun is for me, though I have switched to mostly collecting Japanese cards since the cards are cheaper and the pull rates are much better.