This is the largest amount of cake I have ever been asked to make.  I need to feed 214 give or take.   I have no idea how much buttercream I will need to make.  She wants a very small wedding cake for cutting and the rest as sheet cakes.

Im making a

1-9" round  (covered in fondant)

1-6" round (covered in fondant)

1- 9x13" rectangular

1-7x11" rectangular

2- 10x10" squares

Cakes will be 4 inches high. 

The 2 Tier will be with cream cheese frosting but the other cakes will have buttercream and raspberry filling.  This is for a family member's wedding.  She is only paying me for ingredients, as this will be my first wedding ever. I know... I know...what the heck was I thinking doing this for free?? It's ALOT of of work.  Should I torte the cakes so there are 4 layers or just keep it simple  with two layers?  I wasn't sure how two layers would be with the filling but if I do 4 layers I may have no sanity left.  I am hoping it will all come together, will be a good learning experience, and I can say I have done a wedding. Now that I know how many people she is having I am slightly panicking lol.  But I will get it together!  Please help.

Bless your heart!  To make it easier on you, I would go with just the 2 layers, not 4.  Not sure about the buttercream, as each recipe makes different amounts.  Rather have too much than not enough tho, especially since she is paying for ingredients.  Good luck!

I agree with @cutiger, go for two layers to keep your sanity. If you were actually getting paid for all your work it would be a whole different story, but I've done my share of caking for free to know that no one really appreciates the work you put into it.

As for the buttercream, I don't really have a formula and go by feel. I work with Yolanda's IMBC recipe and I normally use anywhere from 1 to 1.5 batches for a 4-layer 9" round.

Good luck with the cake, make sure you post photos!

I agree with both other comments. 

Stick with 2 layers, I do sheet cakes and 1/4 cakes with 2 layers and filling it turns out great. 

Keep your sanity! I would make extra buttercream regardless. 

Thank you @youngj ‍ , @caketownathens ‍ and @cutiger ‍!  I will go with 2 layers. I will do a layer of buttercream with a layer of raspberry filling right on top and a buttercream damn.  It should be sufficient. I will post pics. Thank you for your prompt reply, I appreciate it!

Making just 2 layers per tier also helps a bit with stability.  Just don't overfill .... pipe a dam w/tip 12 (not a coupler w/o a tip as many recommend) and fill just to the top of that dam.  As for how much b'cream you will need the rule of thumb is one batch of b'cream using 2# of sugar for every cake mix used.   From the list of pan sizes you posted I'd say you need  3 or 4 batches of b'cream.  That should give you enough to use some as filling & crumb coating along w/finishing the sheets & 10" sq tier.