To be fair BD will be upgrading all the purchased frigates with FM-90 SAM, C-802 AShM, and they will all have a anti-submarine helicopter. While it would be better to go for frigates that are armed with VLS medium range missiles, those would come in at around 400 million dollars each as I presume that China would not release their best frigate(type-054A) to us at this moment in time. There is a talk of a new Chinese frigate similar to Type-054A which will be produced for export and this will be something that BD could look at purchasing down the line.
And don't forget that BD will be getting 4 of the latest Chinese Type-56 corvettes so there is a nice number of decent warships that will be coming on-line over the next couple of years.
To summarise by ~2015 BD Navy will consist of:
5 frigates that will have FM-90 SAM, Otomat Mk. II Block IV AShM;C-802 AShM and anti-submarine helicopter
4 Type-056 Corvettes that will have FM-90 SAM, C-802 SSM and anti-submarine helicopter.
OK, this is no match for India but it will be at least as powerful as the Pakistani Navy if you take out their submarines. Then maybe the air-force can then be looked at for some serious modernisation