During our recent trip to Dudhwa National park,, we were about to make the same mistake for the sake of finances but Sweet Candidae (ie my husband) suggested that we go by taxi and to our surprise it turned out to be a wise decision as we would have been at sea without our own transport.
It took a steady 10 hours from Delhi but was the effort worth it!!!!! We stayed in a lovely place called Sonaripur about ten km. inside the jungle from the reception.
SONARIPUR tourist lodge

Oh boy! I was reminded of SD Burman's "Prem ke pujari hum hain ras ke bhikahari" song. "Kahan yeh himalya aisa ,kahan aisa paani......."
The place actually gave you the raw jungle feel as its management hasnt entirely given itself to making it convenient for tourists. It was so quiet out there that we could actually hear leaves (or was it dew drops ?) falling as evening neared.

Roopkali and her baby. Unfortunately the ele calf died after a month of its birth in January 2008.
The roads to the heartland were unlighted making it actually scary to pass by car at night. During our stay therei n DEc. 07, the park was visited by a herd of wild elephants and it was fascinating to see their basketball sized footprints here and there. 
RHINO MOTHER RAJESHWARI AND HER BABY
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SWAMP DEER IN THE TERAI (means wetland)IN THE MIDDLE OF ELEPHANT GRASS
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AN ANTHILL --Baddal, our guide, Sanjiv, Jayanth.
Anthills take decades to buid . Our sages (rishi Vishwamitra etc).went so deep in meditation that anthills would grow above their heads.

A MACHAAN --- A PLACE TO VIEW FROM.
The reason for our choosing Dudhwa that happens to be a relatively unknown or less travelled park is my chancing upon a memorable book by Billy Arjan Singh titled " the Prince of Cats" wayback in 1991 at the reference section of Indore University Library. Incidentally, my "sweet candidate" happens to be one of those who doesnt find it easy to get leave from his work..After fifteen years of "Kitne din yeh dil tersenge, ik din to badal bersenge" ,we ultimately took off to Dudhwa..
Another pressing reason was an interview that I heard in passing of Bill Arjan singh. He looked very very old.about ninety. It proved to be the greatest attraction for us. ----- Meeting the Legend.in person..
Billy Arjan S. , me and Jayanth, my son
It was awe inspiring to see how this man had single handedly managed to save this part of Indian forests and its wild creatures.His little house was full of pictures of his different leopards and tigeresses that he had hand reared and then successfully reestablished in the jungle.
Incidentally, he has founded an NGO named BIlly's Ark- Tiger SOS. His associate Kaushalendra Singh has filed avery interesting petition at the HC of Lucknow. See WIldlife News of Jan 2009 in my blog.