birkenstocks are very comfortable, good arch support.
but don't wear a brand new pair, they need an initial "breaking in" period. thought if you purchase a soft footbed pair, those are more forgiving.
with the bigger yoga gyms it would depend on the package you take (monthly, year, 2 yrs)
but the smaller yoga studios usually have a per-class rate that you can look up on their site.
has anyone tried l'operetta in boat quay?
owned and run by japanese working towards vera pizza napoletana certification (if they haven't received it already..)