Just keeping kids alive until their 18th birthdays is expensive enough. You shouldn't have to break open their piggy banks to give them the occasional cultural experience. The Dallas Theater Center apparently understands this and offers Pay What You Can nights for select Sunday night preview shows. Drop a not-unreasonable $5 a head with a family of four and you'll get your entire clan in for less than a single ticket might otherwise cost. Or donate nothing, if your conscience lets you. With 2009-2010 productions including It's a Bird...It's a Plane...It's Superman, A Midsummer Night's Dream and, of course, the annual performance of A Christmas Carol (which will be presented for the final time in the Kalita Humphreys Theater), there are plenty of opportunities to get them away from the television and let you check out the innovative new Wyly Theatre.