I think this counts as both extravagant and a bit odd:

My personal favorite is one I haven't done in a number of years... it involved using three sets of sheets to create a homemade suspension rig hoisted from a series of wood planks above me, some fuzzy cuffs to help restrict movement a bit, a memory foam sample block that had been sewn to a better shape for this purpose, a hitachi wand with a potentiometer to lower the amount of vibration on the wand which was set up to connect to two strings via pulleys attached to the wooden bars to increase/decrease the setting, a collar attached to a system I don't quite remember how I set up that would apply a slight amount of tension depending on leg positioning, a mattress only about 6 in below the minimum suspension point, three sets of EMT shears in reach while in the suspension, and a room that was entirely dark except for the tv the porn was playing on (when I had it on). I had it set up so that I could move my body with a bit of effort to have my penis hit the wand just underneath the thin piece of shaped foam and rub against it or just hold there.

I had the apartment to myself for a week and used it five or six times for lengthy sessions once I got all the settings tweaked correctly. I think I may have thrown in a few other toys, but that was the main setup. I probably reinforced some of the sheetwork with ropes too, but basically used them to make a long-term comfortable body harness that could have once comfortable and two or three stressed positions. That took so much effort to set up for a temporary rig, but it is one of my proudest masturbatory achievements.