shold i buy blackberry 8520 for web browsing it it right for me.

avoid a blackberry if you want a good browser...why dont you go for Nokia C5 (minus the crappy camera the phone is good) or the Sony Ericsson Zylo. Sony has got a Netfront browser which is a good at page rendering.

Good Internet browsing = Android phone + HVGA resolution screen. Avoid everything else...

The cheapest options are

1. Micromax A70 -- 7000+ (yesterday was on Ebay for 6750) -- Micromax A70 - Full phone specifications

2. Spice Mi-310 -- 6500+ (on Saholic) -- Spice Mi-310 - Full phone specifications

But I recommend LG Optimus One P500... Should get it around 9k on Letsbuy after discount coupon RCOMLB1

For browsing get a good touchscreen phone. Choices already given above. More available if you stretch your budget though.

BB are good but not better than the above given phones.

One of my friend had buy BB Bold 9700 last week. its nice but i think its in 12K so if you starch you budgets little more you will get good mobile in Blackberry.

If your main purpose is browsing, then Blackberry is not advised. Go for a good touch screen android phone. For your price range the best would be Samsung Galaxy Pop Rs.7899 - @Saholic

If you prefer non-android phones you have the option of Sony Ericsson txt pro CK15i,
Nokia Touch and Type C3-01, Nokia Touch and Type X3-02 etc. You can get these between 7800-8000. All good and popular models.

Btw, AndroidFan's suggestions(A70 and Mi-310) are also cool, at a lesser budget than yours.