I'm with Roxy. I used the glass out of a cheap picture frame that I bought from a $2 shop.

Shattering should not be a problem because the whole sheet is being heated at the same time, so expansion will be even over the whole sheet. Also, heat bed glass is being heated to only a little above the temperature of boiling water, so it will take it.

So go to a Cheap Shop and spend about $5 on a picture frame. Then go to an Electronics Parts store and buy a strip of LEDs (9 LEDs will do) and a simple bedlamp switch for about $10 total. That will leave you $13 to buy a 9gm servo and a micro-switch for a bed leveler.

Problem solved!

Old Man Emu