I have tried various online groceries shopping before, i have not much problem with any of them. However, I think it depends on what item you are getting because some items are no available/limited on certain website. Look through the one you mention "Purelyfresh", understand that they have a promotion going on (Seems quite worth it, SGD 15 off first purchase). Perhaps you can give it a try and let us know your experience? They seem to have relatively good reviews on their facebook page but oh well.. no harm trying =) good luck!