I am not really a budget traveller, so I can't really talk to everyone's requirements, but I live very close. My dad visited recently and stayed at Ambassador. That's actually pretty good value, and nowhere near as far down the soi as some of the options presented. Soi 11 is extremely busy, and very crowded. There's a lot of construction happening at the moment, blocking half of the already-small sidewalks. Don't get me wrong, I really like Soi 11. The far end is rad - really nice bars, restaurants. Nice hipster boho vibe. Strong recommend. But it's a long walk down and won't be a welcome walk all the time.
If staying at Soi 11 I'd recommend staying more towards the middle, and closer to Sukhumvit end. Grand Swiss, Ambassador, etc. You'll save money being further down, but I'm not personally sure it is worth. It's one of the most crowded side sois along the stretch, especially late at night. IMO you'll value a short walk to Nana BTS more than a short walk to Insanity Nightclub.
As another bit of unsolicited advice, bear in mind that Soi 11 isn't very near anything. It's half way between Soi Nana and Soi Cowboy. Probably more Nana-end. But it's certainly not a close walk to either, and will require a taxi to get a notoriously lazy bargirl/ladyboy to come home with you. Only CIB is reasonably close, and you'd still need a taxi/tuktuk/motosai to get there. And ironically that pretty much has to go via Nana to get to the right side of the road.