@Push,
You haven’t mentioned the carat & clarity of your blue saphire. But however, natural blue sapphire can come as low as Rs. 100 ($2) per carat but their quality would not be appropriate for wearing on a ring.
So, don’t worry about the price if you can afford it, worry about whether it is natural and untreated or not because the open market of sapphire is very complex as their are many treated, duplicate and fake stones in the market and many traders fail to identify themselves.