Well, the conversion prices are a bit off. The $250 online price already contains some savings on it in US, but if it was to be bought from a authorized dealer in India then it would be $320+12.5% V.A.T. The Blackstar ones will cost around 19k (unless it's last year's stock) through a dealer today if he is getting it from US. But if it's from UK then the price might be lower, can't say for sure though.
Since you are only intending to get one preamp pedal that does Clean & Metal, then the HT-Metal would do. You would have to bend over to alter the settings for the in between sounds though.The Tech 21 Character series would work too, they respond to the guitar's volume knob very well. But you will need atleast two to get both clean & gain for quick switching. If your going to add a pedal after the preamp pedal like a delay/reverb then you may need a DI box as well. A mono DI box would do.
Before you place an order for one of these, make sure you are comfortable with not having an amp on stage. At the next gig during soundcheck take the amp off the stage & point it away in the direction opposite to your ears and check if you are okay with the venue's monitor alone. Otherwise you'll eventually end up having to drag the amp along again or get a personal monitor which will again get tiresome to lug around unless it's in-ears
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