Last summer I went with my buddy around 8 or 9 to Sundays@Space and used a reduced admission flyer for around 20/25 Euros. We were mashed up from partying the night before and thought we could get in cheap, leave with a stamp and sleep at the hotel and then return later. What we found out was that the only people who are allowed to return once are those patrons who pay full price (approx. 50 Euros)
There's all kinds of rules that Space have with the wristband passes, sometimes they change the colors during the night and therefore have an 'expiry' time on them - usually depends on how busy they are - ask when you pass over your cash!