and some are++ Here is what I did to get free 'samples' of textured glass(also known a shower door glass)
I picked up some OSpec green pointer for aroung $5 each w/free shipping- I stopped at several 'Glass n Mirror' shops on my travels- I ask for the manager- explain what I will be doing with thier glass and show them a quickie demo == If they happen to be busy I dont push it-- I tell them it is used for a background for my DJ friend= THEN I give the manager the green pointer so he can check for me and they save me scraps== some can be often found in thier dumpster too. best 5$ I have ever spent.

Another source is thrift shops- bring a pointer as some are impressive ( like glass doorknobs[360 degree) and textured candle holders) while others just dont do much==

For cheap motors check the vac 1/3 rpm from Fred at Surplushed and clock motors with second hand 1 rpm and faster is IMO not as cool as slower.. depends upon the music I guess.