ANeed to do a 10" 3 layer cake chocolate and vanilla with chocolate chips cookie filling butter cream frosting -cookie monster design- debating in how much to charge $50?

If you are happy charging $1.19 per slice (I am basing that on the Wilton charts saying a 3 layer 10" cake would serve 42 slices), then yes, do it for $50. 

A$50 would probably be about $5 an hour after your expenses. That is not a good hourly wage.

ACookie monster is copyrighted so you would need permission from Sesame Workshop in order to legally sell the cake.

As for pricing, you need to take into account your ingredients, labor, and overhead costs from your business license, food safety certification, health permits, insurance, etc. plus a profit. Check out the Pricing Formula link in my signature below for more info.

also any cake over 4" thick usually requires supports so you would need to figure that into the cost.

Thank you for all your responses!  After telling the client the price of the cake which was $50 she stated that it was way over her budget and that she was going to get a cake from the supermarket.  Well I guess you can't please everybody

thanks

Heavenly Cakes

thank you for the infomation