Nope - if you want to go true budget then it is a different story. Yes you can rent a tank for $7 in tulemben and swim to the wreck but of course it's better with a partner ;-).
If you want budget but comfort, go to the farthest north "resort" it's kinda run down but they have refurbished a few bungalows with AC etc. it's very peaceful perched in a coconut grove -but has seen better days. I love it there. the new bungalows are about $25 per night. It's called Puri Madha - the number in the Lonely Planet is wrong so best to just show up. rental gear is pretty sketchy & so rent tanks from the first dive shop you come to before you turn down the long road. It's just past the public dive access park.
If you want top notch - try absolute - airconditioned vans, videos to keep you entertained, new gear & a compressor that you can count on to be serviced. If you want cheap diving and wild west. Follow my above directions but don't be suprised if you meet a few 8 legged friends. The new bungalows are actually quite nice. If your wife doesn't need posh she might enjoy a few days of reading under the coconut trees ;-). It's extremely relaxing. I stay in the cheap $6 rooms

. The dive prices in bali will probably be closer to $28-or $35 - maybe there is shore diving in Ahmed? I don't know???
If you get tired of diving at the wall/wreck in tulemben take a guide & local boat to surrounding sites. It's really cheap.
Have fun. We may be neighbors ;-) Feel free to PM me for any other advice. Most import thing is to understand that bali people love a great sense of humor & charging you more is a game. If I remember right their salary is about $3.50 us a day - so value your dollar - keep a sense of humor and bargain for almost everyting