By the time you pay for the shipping it's gonna cost more than Singapore .... I shipped iPhone covers only costs like 100+
well it really depends on individual sites, everynow and then if they have flat rates shipping promos then definitely will be cheaper.
shopping from those sites is just another avenue for you to get items that are either OOS locally or not avail in SG's boutique but not to replace shopping physically at the stores entirely.
the sales in the local Prada boutique usually CMI one, but from some of this sites they offer good stuffs and ish sometimes discounted as well.
even those concierge shopping gateways charge admin fees for the services they've provided.
not sure how you paid for shipping of 100+ for just iphone covers.