At that time , few people who were abroad in Uk, us, Aust used to request them and we posted . Old songs later came through Eranga-Tharanga (something like that?) logo and think it also belonged to Tharanga. Intially they were Rs. 50 and this is more than Rs 500 -1000 now. The quality of the cassettes were very poor(not the songs) and most of them played less than one hour too. Few years on Singlanka came to the front with new songs and cassette albums and they were priced same but they did marketing with nice pictures and stayed for a long time and even did first CDs at that time Torana was only doing English songs recording (copying). They did not do a single cassette but entirely thrived on copyright violation business. In fact they continued this even to their shop at Magistic City (this is still there ) in 1990s . At that place while selling sinhala and english cDs done by others (eg Singlanka) they undertook to burn CDs for a price . This was immediately stopped when they started their first CD in 1993?(year not sure)
Irony is now Torana is forefront of Copyright battle and even filed actions against copyrights of their albums.
It is worth for some person to do a proper research on this subject as we hardly see a cassette or 2 in one now.(most popular brand was National(now Panasonic) and next Sanyo., Unic (Upali product with NEC of japan)