unfortunately they all seem really expensive and unsure quality
Here is alternative to rings & necklaces:
One inexpensive thing to do is to find an image of Epicurus online, and then print it out and frame it. Most libraries have printers if you don't have one yourself. The frame won't cost too much if you make it small 5"x7" or 8"x10". This would be one way to create something to place on a small "home altar".
And another aspect to add to a home altar would be to add a few books on Epicurean philosophy - and an inexpensive alternative to books would be to print out the Principal Doctrines, etc. (again this could be done at a library). and bind them into an inexpensive school report folder. Also, there is the option of hand-writing the Doctrines or the Letter to Menoeceus and displaying it on the altar.