On my first trip I'd probably stay in Patts and not return to Bkk, if punting is your main priority.
Accommodation as Jimmy says the rates increase a little in December, if you look on hotel booking sites you will usually pay through the nose, yes you can get rooms in both locations for under £20=1,000b a night.
In Bkk most farang punters prefer to stay in the lower Sukhumvit Rd area, but cost of hotels are higher here as they know farangs will pay, you want to be looking for 3 star business hotels, there are several about, one I visited on soi11 when I shagged a girl from backpage, she said room cost her 1300b, you might be better of emailing hotels to ask the rate rather than the hotel booking sites. Now me personally I don't stay in the lower Sukh area, I stay up in Ratchada at Watana Hotel, no need to book in advance, 24hr reception just turn up and pay for the night 800b a night.
External Link/Members Only as for Patts plenty of mid range options, Queen Vic soi 6 being my recommendation.