I found one website regarding yantra making.
Please check the below details
Saundaryalahari yantras as most powerfull one,but you have to meditate daily after wearing the yantra.It is prepared in golden sheet and 41 days special poojas done with nivedyam.It is enclosed in golden loket and you can wear it.It will cost 17000rs.
Pooja and nivedyam will be done by me.once you are ordering yantra it will take 41 daays to complete all the process and after that i can corier you the yantra.You can see the picture in the following link of my website
I use to prepare all types of yantras which is helpfull to people.Saundaryalahari yantras i use to prepare regularly
Please let me, is it worth investing?