Looking to build a new mtg deck for the new october card sets, any idea what is popular?

vampire is still popular and with it becomes less dominating in tournament, the prices of some of the staples pieces have dropped in price. you can think about that. if you want to keep to your budget, forget about blue/white or blue/black control because anything blue means jace 2.0 which also means $200 JUST for the playset of jace. red deck win is not a bad choice as they are fun to play (not to play against). eldrazi ramp is another affordable option since even the legendary eldrazi is just about $10 a piece and you don't need more than 1 in a deck. you will need a couple of different eldrazi or some other finisher like baneslayer or the like as alternative win condition but even baneslayer has dropped prices so it helps fitting in your budget.

First of all, why haven't you seen M11 and SoM yet? You clearly have Internet access, and the Gatherer is easy to use, so you can easily search through the new cards. Cards of note: all 5 titans from M11, the Planeswalkers from SoM, Wurmcoil Engine, Molten-Tail Masticore, and Ratchet Bomb. Maybe Ezuri, Mox Opal and Argentum Armor, if you like fringe Tier 1 decks.

In the current format, $100 isn't going to get you very far. Remember Jace 2.0? He's up to $80, because 70% of the top tier decks use him. Also, Primeval Titan, Grave Titan, and Frost Titan are $20-$40. Most decks run Jace tMS and Frost Titan if they can afford the price tag, and then run either black or green (sometimes both). Maybe they run Valakut Ramp with Primeval Titan. There's a good Elf Aggro deck out there right now, an Eldrazi Ramp deck (no spawn tokens, only good ramp cards), and a decent Quest for the Holy Relic deck as well. But overall, the current format is "Battlecruiser Magic".

If you want to keep up with the metagame, check out starcitygames.com and the mtgsalvation forums.

@Quento Sakisa: I don't know where you're finding these Jaces but the last time I checked Jace 2.0 was around 90-100 USD.

@Seven44: the tier 1 standard metagame is being dominated right now by blue/white and blue/black control, efldrazi ramp, elf beatdown, white weenie quest (bit hesitant to say dominant bout this one), mono-black aggro, and red deck wins. google is your friend on this one, and the sites that David James mentioned are great.

if you're looking to play some tier 2 whether with ur friends or at FNM level, infect decks with scars of mirrodin is pretty fun, as is blue/white control or even myr decks.

magicthegathering.com has great information for the current state of the game with articles from combos to top decks.

personally I just run a standard mill deck. you use keening stone (ROE) and traumatize (M11) to mill their entire library on turn 6 or 7. that's mono blue so you can splash green for acceleration or black for tutoring.