Err, you'd get a ten people-per-room hostel for those prices, I doubt a room within a reasonable distance.
If you're prepared to spend some cash without going overboard, I highly recommend the 'Aspira Sukhumvit' in Soi 7/1, Sukhmvit Bangkok: modern, clean, girl-friendly (as 99% of hotels are).
Phuket: Yorkshire Hotel: the cheaper windowless rooms are small but pleasant
Pattaya: Golden Ville Spa and Boutique: 10 mins walking distance of Walking Street but, poor quality bathrooms (honestly, who wants to see a frosty image of a girl shitting whilst you're waiting for her on the bed) where the water from your shower just goes everywhere, but otherwise quite nice.
I'll be returning to the Aspira next May and on the lookout for a better hotel in Pattaya this time, closer to Soi 6 than Walking Street. Though I might get a baht-bus if I end up going there.
Honestly, you're going for just 8 nights - unless you want the nightmare of Thai taxi drivers taking you from a cheaper hotel, why not treat yourself to something a bit better?