Thought I'd throw this out there.

I'm not sure how best to spend $100. I'd like a booster box of Avacyn but I'm not sure its worth it. I also only play standard. I am trying to collect all the planeswalkers, so I could put the money toward that.

I'm leaning toward buying a box of Avacyn so I could complete the set, get cards for playing and for trading.

Any ideas?

I had a hundred bucks around the avacyn release and I chose to just preorder 4 cavern of souls and keep twenty bucks for the prerelease(s). It was really the best choice since this way I'm not having to run everywhere trying to get cavern off everyone and if I ever pick them up I can trade them off easy. I would suggest just straight buying what you need rather than gambling for what you need.

Also you may be smart to save that cash for return to ravnica since there are likely to be shock lands to get the value out of your packs.

Buying a box is generally never worth it financially.
Buy singles that you want.

I think that it is funny that no one mentioned M13 so far. Looking at the cards that have been spoiled so far, it looks like a set that I will NOT be getting a box of....

Back on topic - I agree with the others, skip the box and buy the singles that you want.

Buying singles is the best use of your money.

I prefer to buy boxes, although it is probably less cost efficient, but I also usually pull about 100$ worth not including cards worth less than 1$ so I'm not 100% sure, I also don't have a huge inventory so I like to get commons and such as well

I just got an M12 Box for 65$, he has one left.

http://www.ebay.com/itm/2012-Magic-The-Gathering-Core-Set-Brand-New?item=170859136910&cmd=ViewItem&_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D4%26po%3DLVI%26ps%3D63%26clkid%3D68604169216638637

Edit: Looks like someone snatched up the other one.

Thanks for the input. I ended up buying 4 Tamiyo's and a Geist of St Traft.

Note: 3 tamiyo's will be up for trade next week.